Types of Hair Loss and Pattern Thinning in Men and Women
In This Chapter
People have different ideas about what constitutes hair loss and what causes it. Some people see three or four hairs in the
sink after combing and panic. Others don’t think they’re losing their hair until the back bald spot meets the middle bald spot and there’s nothing left to comb. When it comes to figuring out why they’re going bald, some people assume it’s genetic, and therefore unavoidable, whereas others are less accepting and look into every possible way to save their hair.
In this chapter, we define male and female balding patterns, explain why balding occurs, describe how pattern baldness is recognized and classified, and give you some ideas on how your lifestyle can affect your hair.
How do you define hair loss? Do you consider you’re balding when you’ve lost 5 hairs, 5,000, or 50,000? Can you slow the balding process, stop it altogether, or should you just increase your base- ball hat collection and live with it?
Hair falls out of your head every single day, at a rate of about 100 to 150 hairs if you are a Caucasian (Asians lose 80–120 per day and Africans 60–100 per day). You aren’t going bald if your hair is coming out at these rates because that is the rate that new hair grows up from the scalp. If the hair that falls out isn’t replaced by the same number of new hairs, then you have a balding problem. Hair loss isn’t noticeable in the average person until more than 50 percent is lost, which is around 50,000 hairs, more or less.
Why does hair loss occur at all? You were born with your hair, and by simple logic, you should die with it, right? Not one organ in the human body dies as a natural course of aging, yet hair follicles commit mass suicide over time. Other human organs may change over time and become less functional, but they don’t disappear altogether. Is hair loss a type of genetic adaptation? No one knows.
This section looks at the different types and causes of hair loss, including the cause of 99 percent of all cases of male balding: male pattern baldness.
There’s more than one category of hair loss. Can your doctor tell just by looking at you what kind of hair loss you have? Yes, some- times. Hereditary hair loss patterns, the most common type of hair loss in men, have developed into a classical clinical descriptive science. Genetic hair loss appears in distinct patterns, and these pat- terns are almost 100-percent diagnostic for male pattern baldness. The later section, “Norwood classifications for measuring male pat- tern thinning” covers the most common baldness patterns. Also, we discuss the types and causes of pattern balding in the later section, “Common Causes of Hair Loss.”
In women, balding patterns also exist (see the section, “Genetic hair loss in women,” later in this chapter), and a knowledgeable doctor may be able to tell what’s causing the hair loss just by looking.
A small segment of people lose scalp hair uniformly (diffusely), rather than losing hair in specific scalp areas. Uniform hair loss isn’t as easy to detect as other types of hair loss because the hair is steadily lost all over the head. It’s much easier to detect a bald spot resulting from hair loss in a specific area of the scalp from
diseases that cause uniform hair loss to the normal genetics of that particular person.
Hair loss occurs normally and usually occurs at the end of one of the normal hair cycles that all hair goes through. These hair cycles are as follows:
At the end of the telogen phase, a new hair bud appears, signaling the beginning of anagen. (Chapter 2 has more about hair growth phases.)
The hair apparatus starts off producing a baby hair below the skin, which grows longer and longer until the final terminal hair (a full mature hair reflective of what we style every day when we comb out hair) emerges from the pore in the skin. In some adults, the anagen phase may never start, signaling that the hair follicle may have died. If a new hair doesn’t grow to replace the lost hair, the total hair count drops.
Hair grows in natural occurring groups called follicular units (FU). A single FU contains from one to four terminal hairs and one vellus hair (a fine hair amidst the clump of terminal hairs). When a hair isn’t replaced after its telogen phase, the number of hairs in the FU decreases, but the number of FUs remains the same. So an FU starting with four terminal hairs may end up with only two or three terminal hairs as we age or as we undergo some form of balding. When this happens across the whole scalp, the total hair count decreases proportionally.
The older the patient is, the more likely it is that doctors see this uniform hair loss process. About one third of men over age 70 have this diffuse hair loss, which is called senile alopecia. The name doesn’t reflect the mental status of those afflicted, but rather it essentially means that the condition is most common in the elderly. Because hair also becomes finer with age, severe thinning reflects a loss of both hair bulk (in each hair shaft) and hair densities. (For more on hair bulk and density, turn to Chapter 2.) There’s no cure for senile alopecia.
Young men may experience uniform hair loss in the form of a condition called diffuse unpatterned alopecia (DUPA). Doctors believe that DUPA and senile alopecia are similar but for the age of occurrence. DUPA impacts men in their 20s and 30s and doesn’t seem to be responsive to drugs used to treat the classic type of male patterned hair loss. We cover treatment drugs in Chapter 9.
Identifying dying hair cells
Apoptosis is a cell’s internal “suicide” mechanism that causes cell death. The phenomenon has recently been studied very carefully, and what doctors know is that during the transition from anagen to catagen (that’s the growth phase to the changing phase), some- thing happens in the hair follicle development.
The cells within the hair follicles communicate with each other, and certain chemicals secreted in the hair follicle determine which hairs will survive for another growth cycle and which will die. Experts believe that the lifespan of each hair follicle — and possibly each follicular unit — is genetically programmed.
Because some of the hair follicles within the FU survive while others die, there’s some hope that the chemical inducers that determine the survivors can be identified and manipulated to pre- vent hair loss. We have identified some of the molecules that stim- ulate the process but others still need to be isolated. Maybe when all of the molecules are identified and isolated, we can stop the balding process from occurring.
Saving dying hair cells
The causes of cell death are complex. Research has shown that the cells that produce apoptosis-causing chemicals are found in every part of the hair follicle. It’s possible that different types of hair loss are influenced by different chemical problems in the pathways that control cell death.
Although the medical community is identifying many of these chemical pathways, it’s no closer to finding a cure for apoptosis than we would like. Interestingly, apoptosis typically doesn’t occur in cancerous cells, which are thought to be immortal, escaping their natural destiny of living a given number of cell cycles. For example, in breast cancer, a gene called BRCA causes the production of a particular enzyme that blocks apoptosis. Imagine if it were possible to bottle that enzyme to use on hair that’s dying off or, even better, create a cocktail that could make all the cells in the body immortal! At least we can dream.
A number of diseases and conditions cause hair loss, but most people go bald because of the influence of genetics, hormones, and time. Stress may cause additional loss, more so in women than in men.
In the genetic hair loss lottery, Grandpa’s important, but doctors actually look a few generations back on the entire family tree — men and women — in order to determine if you’ve inherited a genetic type of pattern baldness.
Everyone inherits genetic tendencies from their parents. As you may or may not recall from biology class, pairs of DNA segments called chromosomes carry the information that contains the potential for different characteristics. A gene is a single bit of chemically encoded hereditary instruction located on a chromosome.
The genetics of androgenetic alopecia (ANA), also called androgenetic alopecia or male pattern baldness, is complicated. At least four genes are responsible for hair loss. When several genes need to be present for a trait such as hair loss, the trait is said to be polygenic. Genes that are located on the X or Y chromosomes are called sex-linked, and genes on the other 22 pairs of chromosomes are called autosomal.
Currently, doctors believe that the genes governing common bald- ness are autosomal (not tied to the sex chromosome) and there- fore can be inherited from the mother’s or the father’s side of the family. The commonly held notion that baldness comes only from the mother’s side of the family is false, although for reasons not fully understood, the predisposition inherited from an affected mother is of slightly greater importance than that inherited from an affected father. Doctors also believe that the genes involved in androgenetic alopecia are dominant, meaning that only one gene of a pair is needed for the trait to show up in the individual. So even if only one of your parents passed on the baldness gene, you’re likely to have some hair loss.
The inherited gene isn’t always ‘expressed,’ so it’s possible to carry the gene for balding and never become bald. It can skip a generation or two, so only looking at the generation before you doesn’t tell you what may happen on your head.
The ability of a gene to affect you is called expressivity.Expressivity occurs depending on a number of factors, the major ones being hormones and age, although stress and other factors may also play a role. Put simply, a man whose father and uncles are severely bald may have minimal hair loss because the expression of the baldness gene is limited. If you are confused by this explanation, imagine the experts who try to clarify the unexplainable by putting together the many variables and not coming up with a logical, scientific process.
The end goal of gene identification is to manipulate genes to pre- vent or reverse common baldness. But doctors first need to find and fully understand which genes cause the balding process and why are these genes expressed one way in you and another way in your brother.
Hormones are very powerful biochemical substances produced by various glands throughout the body. The primary male sex hormone is testosterone. Testosterone and other related hormones that have “masculinizing” effects are produced primarily in the testicles. These same hormones are the cause of many changes that occur in puberty in boys. The hormones that cause acne and beard growth also can trigger the beginning of baldness. Testosterone is also produced in women from the adrenal glands and the ovaries, and it is produced in lower concentrations than the testicles pro- duce the hormone in men. In women, most of the testosterone is converted into estrogen.
The hormone believed to be most directly involved in androgenetic alopecia is dihydrotestosterone (DHT). DHT is formed by the action of the enzyme 5-alpha reductase (5AR) on testosterone, and it binds to special receptor sites on the cells of hair follicles to cause the specific changes associated with balding.
The presence of androgens (steroid like substances), testosterone (considered an androgen), and DHT cause some hair follicles to regress and die. In addition to the testicles, the adrenal glands located above the kidneys produce androgenetic hormones; this is true for both sexes. In females, ovaries are the major source of hormones that can affect hair. Androgenetic hormones stimulate many of the male sex characteristics we see in adult men. Androgens like testosterone, are converted into estrogens in women, which make women develop their typical female sex characteristics.
The beach is an excellent place to observe hair patterns. Have you ever noticed that men with hairy backs and shoulders often have a bald head or a hair replacement system?
This indicates that the gene for hair on the back and shoulders is separate from the gene for hair on the scalp. Although DHT acts like fertilizer for shoulder and back hair, it causes reduction of head hair in many men.
Early in the 20th century, a psychiatrist discovered the specific relationship between testosterone and hormone-induced hair loss. The doctor noted that the identical twin brother of one patient was profoundly bald while the mentally ill twin had a full head of hair. The doctor decided to determine the effect of treating his patient with testosterone, and injected him (the hairy twin) with the hormone. Within weeks, the hairy patient began to lose all but his wreath of permanent hair, just like his twin. The doctor stopped administering testosterone, but his patient never regained his head of hair.
Testosterone and DHT
The cause of pattern thinning in men is primarily related to two sex hormones, testosterone and DHT. The body converts testosterone into the hormone DHT by way of an enzyme found in various tissues throughout the body.
In men with the genes for ANA, DHT increases the resting (telogen) phase and decreases the growing (anagen) phase of hair. (We explain the growth cycle more in the earlier section, “Examining uniform hair loss.”) Consequently, as a man ages, less hair grows at any given time, and the hair starts to thin as a normal consequence of aging, especially in men with ANA. Eventually, baldness occurs. In men who haven’t inherited the ANA balding genes, the combination of DHT and testosterone doesn’t cause hair loss and may have a lesser impact on aging hair.
Some areas of the scalp are more susceptible than others to the affects of DHT. For example, the hormone doesn’t usually affect hair on the back and side of the head, which is why these areas retain hair. The term “male pattern thinning” is used because hair loss occurs in a pattern — the back and side of the head retain hair but the crown and frontal areas may lose it. The loss may be con- fined only to the frontal area or the crown area based upon the genetics that are inherited from the family tree.
DHT does play a role in the growth of beard hair; body hair; and eyebrow, nose, and ear hair, but doctors don’t clearly understand that role. Sometime after puberty, male hormones trigger a biological clock that makes hair grow in these areas.
In men, the enzyme 5AR activity is higher in the balding area. Women have half the amount of 5AR overall as compared to men but have higher levels of the enzyme aromatase, especially in their frontal hairlines. Aromatase decreases the formation of DHT, and its presence in women may help to explain why female hair loss is somewhat different than hair loss in males. (The section “Examining Hair Thinning in Women” later in this chapter takes an in-depth look at female hair loss.)
The only way to stop DHT is to block it with finasteride or dutasteride, drugs that interfere with DHT production. (See Chapter 9 for more on DHT and the drugs that fight hair loss.)
At present, only finasteride has been approved by the Federal Drug Administration (FDA). Dutasteride is still being evaluated for its safety and effectiveness for hair loss in young men. There are some reports that dutasteride has significant effects on male sperm pro- duction; as such, it may not be approved for men experiencing hair loss. Blocking DHT in women with dutasteride hasn’t been shown to prevent or reverse female hair loss or hair thinning. Its safety with regard to breast cancer, particularly in women who carry the breast cancer producing BRCA genes, is not understood.
Steroids and similar products
Anabolic steroids, the kind bodybuilders sometimes (illegally) use, can cause hair loss if you’re genetically predisposed to it. And there’s a direct link between taking human growth hormone (HGH) and hair loss — probably caused by the same underlying mechanisms as steroid use. Women body builders who take steroids develop some male sex characteristics and some experience hair loss.
HGH has become a trendy anti-aging tool. More and more men are using it as a fountain of youth. Some men combine steroids and HGH because they make them feel better and stronger. But we have seen many men on HGH in our offices with “unexplained hair loss.” No real mystery there.
Many men who take steroids also take Propecia (a DHT blocker) to offset the negative effects of DHT. Propecia blocks DHT and causes a rise in systemic testosterone by up to 18 percent. Indirectly, Propecia may help muscle building if DHT levels go down (from the Propecia) and testosterone levels go up to compensate.
Testosterone is a much stronger hormone than DHT, and the sum of the effects of the rise in serum testosterone from taking a DHT blocker such as Propecia and the steroids may very well produce more hair loss, not less.
Everyone is different, so we can’t conclude if the muscle mass that the men are seeking from steroid use can be offset. Recently, Propecia was found to mask the blood measurements for other steroids when used in athletes, which is why its use is banned for professional athletes.
Fitness-focused individuals may take the following products for their physical benefits, but these products can also cause hair loss:
Hair loss is also a risk for women who use steroids, if they’re pre- disposed to the condition. Women usually take steroids for dis- eases that occur later in life, such as autoimmune disease, temporal arteritis, rheumatoid arthritis.
The mere presence of the necessary genes and hormones for hair loss isn’t enough to cause baldness. Susceptible hair follicles also have to be exposed to the responsible hormones. The onset of hair loss varies from one individual to another and is influenced by genetic expression, the levels of testosterone and DHT in the bloodstream, and age.
Hair loss doesn’t occur all at once, but is cyclical. People who are losing their hair experience alternating periods of slow hair loss and rapid hair loss, and even periods when hair loss stabilizes. The factors that cause the rate of loss to speed up or slow down are unknown.
Most men who have extensive balding develop much of it by age
30. Twenty-five percent of men will show clinical balding by age 30, and half of the male population will show some degree of clinical balding by age 45 to 50. Balding slowly continues into the next decade or two, and then the process seems to slow down as men approach 60 to 65. As this is a genetic process, it is probable that the men who bald later in life rather than earlier also have a form of genetic hair loss, just not the obvious process we see in the younger men with classic pattern balding.
Men who continue the balding process well into their 30s and 40s typically don’t lose their hair as quickly or as completely as men who start balding in their early 20s. About 7 percent of men who are balding develop the most complete form of balding (called the Class VII pattern; see Figure 4-1), in which only the wreath of hair exists around the head. Those men with Class VII balding patterns, usually show those patterns before they reach 30 years old. This wreath of hair is permanent hair in most men and measures about 21⁄2 inches in the mid-back of the head when the balding process reaches completion. Most men who show balding don’t advance to full balding.
To make matters more confusing, the age of onset discussed above reflects the majority of men, yet there are still some men who start the process later in life (in their 30s, 40s, and even 50s).
The most common balding patterns are seen at the frontal hairline where frontal and temporal recession occurs, moving slightly upward toward the top of the head. A bald spot may appear in the crown and when it does, it seems to widen slowly as men age. Sometimes, the crown balding area merges with the frontal reces- sion, clearing a wide bald channel in the center of the head that we jokingly call the “runway.” Genetics determine the final pattern.
When the body experiences stress caused by a traumatic experi- ence, nutritional deficiency, or illness, the rate of hair loss can increase. For example, a 39-year-old patient of Dr. Rassman lost his
4-year-old child to cancer and within just a few months, the man lost all but the permanent wreath of hair around his head. He probably had the genetics for this balding pattern, but only expressed that pattern when it was induced by this extreme stressful situation.
Women’s hair seems to be more sensitive to the effects of stress than men’s hair. This may be because women with a genetic predisposition to hair loss usually have a higher percentage of fragile miniaturized hair, which is hair with thinner than normal hair shaft thickness. But unlike in men, the hair loss in women is often not permanent or complete.
Stress generally causes a type of hair loss referred to as telogen effluvium, which is very different from androgenetic alopecia (dis- cussed earlier in this chapter). Telogen effluvium is the reversible shedding of hair in the resting phase when the body senses, for reasons that are not clear, that it needs to divert its energies. Therefore, stress temporarily changes the amount of hair that’s shed, but the lost hair is likely to grow back. Turn to Chapter 5 for more explanation of telogen effluvium.
Some doctors assert that a lack of blood supply contributes to hair loss. Bald skin gradually loses some of its blood supply and as a result becomes thin and shiny. These changes, however, come only after the loss of hair and is not the cause of the hair loss.
Hair follicles are some of the most rapidly metabolizing cells in the body. Growing hair requires the proper oxygen and nutrition that comes with a good blood supply in a healthy body. When hair follicles are transplanted into skin grafts or scar tissue, both of which may have a relatively poor blood supply, the presence of the grafted hair causes the local blood supply to increase. The end result is that as the hair grows, so does the blood supply.
Can you eat yourself into a full head of hair? Probably not, but environmental factors, including what you eat, can cause hair loss. The following list breaks down some of the more prominent factors:
common around the world, but continued intake of selenium
to the point of selenium toxicity produces hair loss, among other effects.
Doctors hope that science will discover ways to treat pollutant contributions to hair loss with topical lotions to block the effects of the pollutants on the hair follicles.
Looking at Male Pattern Thinning Pattern thinning is a specific kind of hair loss that occurs gradually over time. Both men and women can experience pattern thinning,
but they experience it differently. In men, pattern thinning some-
times goes by the scientific name androgenetic alopecia (ANA). You hear a lot about ANA, as it’s the most common reason for hair loss in men. Easily 98 percent of men who are balding have ANA.
Men with ANA usually first notice a thinning or receding hairline in the front at a fairly young age. The pattern progresses to thinning on the crown of the head that may slowly thin over a decade or more. The pattern thinning process tends to begin during early or mid-20s, possibly with some thinning in the teen years, but until the thinning reduces the hair density by 50 percent most of it goes unnoticed.
For the man with patterned hair loss, general areas thin but may not become completely bald initially. Over many years, the hair loss can progress to complete balding, but it’s also possible that total loss of hair may not occur.
Male hair loss starts when hair shafts grow thinner in a process called miniaturization. As fewer hairs remain after shedding starts, men notice, especially in bright light, that their hair has a “see- through” look. They generally start off denying what they are seeing, and then eventually panic sets in.
Because male pattern thinning is a genetic condition, a man who comes from a family with many bald members is more likely to be on the lookout for baldness symptoms than a man from a family with full heads of hair. However, because of the nature of ANA, genetics can play tricks on men.
In some families, balding isn’t transmitted to the offspring, while in families with full heads of hair, the genes for balding may lie dormant in one generation and then just appear in the next. All too often, a young man can’t believe that he’s balding because he can’t find relatives on either side of the family with balding; the reverse is also true — a man with a full head of hair may see extensive balding in his family line. It’s just a role of the genetic dice, we suspect.
Nine out of ten times, men first discover that they’re shedding when their shower or bathtub drains get clogged with hair. Regardless of details of the discovery, they may adopt a different hairstyle to cover the signs of hair loss. Some men may abandon combing their hair straight back and adopt a side-to-side combing style that more easily hides thinning hair, continuing this sleight of hand to a point when even this style doesn’t cut it. Some men just comb their hair forward so that no one can see what’s happening to the front of the head. Look at Rudolf Giuliani and John
McCain, who use comb-overs as their slight of hand that is not as slight as they think.
Some men are all too aware of their family’s balding problem. They may have teased their father or older brothers about their balding, but it’s not so funny when it happens to them.
Those who look for signs of balding or thinning have the opportunity to catch it early. Despite the drug company Merck’s promotion of Propecia, many men are unaware that hair loss can be slowed, stopped, or possibly reversed if they take this drug early enough in the pattern thinning process. Treatment can be very successful if the diagnosis is made when the hair loss first become evident, hopefully before substantial thinning has occurred.
The only way to determine if you’re at the very beginning of the balding process is to get your hair and scalp mapped out for miniaturization, which is always present when the balding process starts. Mapping requires the use of a video microscope, which examines the hairs all over your head for miniaturization.
As experts in this field, we believe very strongly that if a man is concerned that he may develop hair loss, he should see a doctor to map the scalp hair for the frequency and distribution of miniaturized hairs. Even early pattern thinning corresponds to the balding patterns seen in the Norwood Classification Chart (see Figure 4-1), so doctors can predict the eventual hair loss pattern early on. Annual scalp hair mapping can detect the earliest signs of genetic hair loss before balding can be detected by the naked eye. It can also follow the benefits or lack thereof, of the treatments for balding.
For men, the drug Propecia can be effective at stopping the balding process or at least slowing it down. Unfortunately for women, there’s no comparable drug other than Minoxidil, which works only in a small percentage of women.
Most people think that bald is just plain bald, but doctors measure male pattern thinning by degrees using the Norwood classification system. Dr. O’Tar Norwood devised this classification system in the 1970s, answering the all-important question, “How bald am I?”
Norwood provides two classification systems, one for regular male pattern thinning and one for Type A pattern thinning.
Regular male pattern thinning
Figure 4-1 shows the Norwood classification system for regular male pattern thinning. Under the regular classifications, hair loss is divided into seven patterns. Men may progress from one pattern to the next, or they may develop any one of these patterns all at once as the hair in that pattern thins to complete baldness in the pattern identified on the chart.
The majority of men with pattern thinning follow the regular pattern, with hair loss starting in the front and progressing slowly (front and back) in two different areas (Class IV and V). On rare occasions, a man may just bald in the crown with minimal frontal balding (Class III Vertex). Over time, the frontal and crown areas enlarge and merge, and the entire front, top, and crown of the head may become bald (Class VI or VII).
Baldness in some men progresses such that they fall somewhere between the different stages; in other men, hair loss comes to a halt, and they remain in one stage without progressing to the next. Although there’s no general agreement on the statistics for the frequency of balding, it’s believed that advanced balding (defined as a Norwood Class V, VI, or VII pattern) occurs in about 35 percent of balding men.
In 95 percent of men, the 1⁄2 inch of hair on the front of the forehead is lost in the younger years, and the hairline recedes into a mature male hairline (somewhere between a Class II or III pattern) with a characteristic convex V-shape. This change from the concave juvenile hairline (also a typical female pattern hairline) to the convex mature male hairline is common and not necessarily a sign of oncoming baldness.
Balding starts at Class III in the Norwood regular classification system (see Figure 4-1). The juvenile hairline is found in all pre- pubertal boys, whereas a mature hairline appears in 95 percent of Caucasian men ages 18 to 29.
Here’s an easy test to find out if your hairline is in its mature position: Lift your eyebrows high and check the distance between the highest crease on your forehead (in the middle) and the beginning of your hairline:
it’s a mature male hairline.
you have frontal balding.
A very small percentage of men keep their juvenile hairlines for many years (former Presidents Ronald Reagan and Bill Clinton are examples of the lucky few). Some men have a persistent forelock, thick hair at the central front of the forehead that remains despite pattern thinning or balding around it — like an oasis in the desert (talk-show host David Letterman is one example). The frontal fore- lock doesn’t appear to be subject to the ravages of DHT (refer to the earlier section, “Hormonal influences on hair” for an explanation of DHT), and the frontal hair tends to retain its thickness much like the hair on the sides and back of the head.
Unusual genetics: There appears to be a different genetics in
some parts of the head in some people. The 2⁄3rd inch of the juvenile hairline and the frontal forelock have, in some people, genetics that do not reflect the rest of the frontal part of the head. On rare occasions, we have seen men lose all of their hair in front and on the top except for the frontal 2⁄3rd inch of hair (just as they had it at the age of 12). This pattern looks strange and each man that presented with this unique pattern of balding tended to exploit the frontal 2⁄3rd inch by letting it grow out 6–10 inches in length to comb back over their balding head.
Type A pattern thinning
The set of figures in Figure 4-2 shows Type A pattern thinning. Type A thinning is less common than the regular pattern covered in the preceding section, occurring in less than 10 percent of men. In this pattern, hair loss progresses from the front to the back, pos- sibly reaching the crown of the head and stopping about where the swirl exists. Type A pattern thinning is most dramatic in front, and for that reason, Type A men tend to look quite bald even though their hair loss is minimal. Actor Gene Hackman showed the Class A pattern balding for most of his career, and as one followed him in films, his balding pattern creeped from front to back in the classic A pattern.
Evolutionary theories for male pattern baldness
Can male pattern baldness be explained by sexual selection? In other words, are males programmed to go bald in order to attract females? Scientists have suggested that, in primitive societies, an enlarged forehead may have conveyed increased maturity and social status — traits that historically have made men more attractive to women.
In Sex, Time, and Power: How Women’s Sexuality Shaped Human Evolution, (2004), author Leonard Shlain suggests that bald men made the best hunters in primitive, hunter-gatherer societies. Thanks to their lack of hair, bald men could peer over the bush and spy game animals without the animals’ recognizing them as men and flee- ing. Being better hunters, the bald men were better providers, which made them more attractive to women.
This theory is certainly something to think about when you notice your hair thinning: Women may instinctively like it more than you think.
Women are generally more attentive to the appearance of their hair and notice the see-through quality of thinning hair early on. Most women with thinning hair don’t lose enough all at once to clog the drain, so problems with styling may be the first sign of the female genetic balding process. This is fortunate because the slow onset of thinning allows women to adjust their styling to compensate for their hair loss.
Most women are able to conceal thinning with a new hairstyle, up to a point. Layering, a pulled-back style like a pony tail, or a bun can hide thinning hair fairly well. Or women can use hair extensions or other hair systems, which we discuss in Chapters 6 and 7.
Regardless of how well they may be able to hide it, hair loss is a psychological challenge for women who fondly remember the luscious, thick hair of their youth and see it coming out in bunches on their hairbrushes. Thinning hair can make a woman feel older and less sexy.
This section looks at genetic female pattern hair loss and other causes of women’s hair loss.
There are a number of types of identifiable hair loss in women, and they differ based on their causes. The cause of female hair loss is reflected in the pattern, so doctors look to the pattern of loss to get an idea of the cause and how to treat it.
About 10 percent of women experience the classic pattern of genetic hair loss, which is an intact frontal hairline for the first
2⁄3 inch or so and hair loss behind that persistent hairline. Another recognizable pattern of genetic hair loss in women is hair loss con- fined to the top of the head, sparing the leading frontal edge of the hair line. Some women with genetic hair loss experience a diffuse hair loss, which is a thinning of the hair all over the head (including the sides and back of the head) and isn’t confined to any particular area. This is more common in postmenopausal women, although it does show up in younger women as well.
Perimenopausal women frequently experience pattern thinning that’s usually worse in the front of the thinning area, about 2 to 3 inches behind the hairline. Over time, it progresses as far back as the swirl (the place in the crown where hair changes direction and produces a vortex); the thinning areas may spare the sides and back of the head. For perimenopausal women, thinning tends to be diagnosed in the 30s or 40s. It is present but less frequent with women in the 20s. The good news is that once the thinning is rec- ognized in these women it is generally stable over time and does not show the progressive nature of the male balding patterns, at least until they reach menopause.
On the other hand, an advanced presentation of uniform hair loss, called diffuse unpatterned alopecia (DUPA), leads doctors to narrow the type of hair loss down to a few distinct possibilities, including female genetic hair loss or senile alopecia.
Generalized thinning isn’t always genetic, and women should undergo a complete medical examination including a wide variety of laboratory tests. (We touch on these tests in this chapter in the section “Medical causes of female hair loss” and in detail in Chapter 5.)
In women, there’s a distinct relationship between mother, sisters, aunts, and grandmothers when it comes to thinning hair patterns. When we take a careful history from women with thinning hair, far more than half of the women we interview with balding or thinning have female relatives with a similar problem. When one recognizes this in the family history, we generally ask these women to inquire on the course of the family balding patterns from a timeline perspective.
Genetic hair loss is relatively uncommon in women and is generally referred to as female pattern hair loss or female androgenetic alopecia. In women with this condition, the common pattern differs than that of men. Whereas the pattern in men follows the Norwood classification (refer to the earlier section, “Norwood classifications for measuring male pattern thinning”), the postmenopausal pattern in women is characterized by diffuse thinning starting just behind a normal hairline and extending to and beyond the swirl.
Unlike men, adult women with typical female postmenopausal androgenetic alopecia often have significant levels of miniaturization (decreased hair shaft thickness in some hairs and loss of hairs within the follicular unit) in the back and side of the scalp.
Miniaturization causes hair shafts to become thinner over time before falling out, and the higher degree of miniaturization present indicates an unstable hair loss process throughout the scalp.
In some women, the genetic pattern of hair loss is associated with an increase in male sex hormones (androsterone, testosterone, and DHT), but in most cases of genetic hair loss, it occurs when the sex hormone levels are normal.
Compared to men, the mechanism of balding in women is less well understood because their hair loss isn’t as directly related to the presence of DHT. The enzyme aromatase appears to have a role in causing female hair loss and may partially explain the different pat- tern when compared to men. The loss of estrogens in post- menopausal women means that the protection against female genetic alopecia is withdrawn, bringing on the thinning.
Women who develop pattern balding later in life also have a genetic component to their hair loss, but the association is less strong. The changes in hormones that occur around menopause are an obvious contributing factor.
Because genetic hair loss presents itself differently in women than in men, a different classification system is used. Doctors use the Ludwig classification to describe the thinning that women experi- ence. A Ludwig type I is associated with a mild widening of the part width. Patients who fall into type II have increased thinning with moderate widening of the part. Type III patients have significant widening of the part width. Figure 4-3 depicts types I through III.
A minority of women develop pattern balding in a distribution that’s similar to men. These patients are better classified using the Norwood classification system. Because these women have hair loss mainly limited to the front and top of the scalp that doesn’t affect the back and sides, they may be candidates for hair trans- plant surgery, which we discuss in Chapter 13. About 15 percent of women have this patterned balding.
Apart from genetics, female hair loss can stem from a variety of medical causes. This section looks at those causes, from the general to the more specific, including postpartum and menopausal hair loss.
Underlying medical conditions
In women, many medical conditions may cause hair loss, including the following:
See Chapter 5 for a full discussion of medical problems that cause hair loss.
As a woman experiencing hair loss, you should first be evaluated by a dermatologist to make sure that no underlying skin conditions are contributing to the hair loss. They may require a treatment different and may require a biopsy to rule out the presence of certain skin diseases like diffuse alopecia areata. Your family doctor can do the required blood tests for the various diseases that may be present. Dermatologists are the best to hone in on a diagnosis.
Blood tests check the following common contributors to female hair loss and can help rule out some identifiable medical conditions:
It’s important to note that even after a medical condition has been corrected, your hair loss may still persist perhaps because of a “switch” in your genetic makeup that’s turned on when the medical insult occurs. After the hair loss starts, it may be difficult to turn off this switch. The hope is that your hair loss will slow down after your medical condition is treated or cured and any deficiency of your overall hormone balance is corrected.
Baby blues: Postpartum hair loss
Pregnancy alters a woman’s overall hormone configuration in many different ways. When hormones change, hair becomes a target organ for change in some (but not all) women because the rapid growth of the hair cells reflects changes in the overall hormonal environment in the woman’s body.
When you’re pregnant, your production of the sex hormone estrogen increases, which prolongs the growth (anagen) phase of the hair cycle. During pregnancy, many women are delighted to dis- cover that their hair is thicker and more lush. After the baby is born, however, estrogen levels drop and more hair lapses into the resting (telogen) phase. Consequently, your growing hair may fall out, and because the resting cycle lasts two to six months, it may take time to see the hair return to its growth phase.
Because hair grows at about 1⁄2 inch per month and doesn’t start growing again until the rest cycle is complete, it can take up to a year for you to get your “old” hair back. In that period, you may think you’re going bald; don’t worry, you aren’t. In nursing moms, the resting period can take longer than a year, and it may take more than a year for hair growth to return to previous levels.
Anemia and hypothyroidism also can contribute to postpartum hair loss. You can find out more about these medical conditions and others in Chapter 9.
Menopause-related hair loss
Over 50 percent of women going through the hormone fluctuations associated with menopause experience significant hair loss. The drop in estrogen levels in postmenopausal women may put the hair in a prolonged resting phase; this phase is particularly important for those women who have inherited female genetic hair loss. Unfortunately, doctors don’t really understand the mechanisms by which the withdrawal of estrogen causes hair loss in women, but they know that it occurs. Women who lose estrogen support have many changes in their bodies, of which hair is only one. There are books written on the use of hormone supplements for managing menopausal changes in the body, and this book is not meant to deal with these complex issues.
Labels: Hair Loss
