Hair loss (or Alopecia) may come as a surprise, but there is no mystery about it. There is always a cause and the cause can be diagnosed by a physician or hair restoration specialist who can recommend appropriate treatment. Everyone loses hair, it's normal to lose about 50-100 hairs every day. If you see bald patches or lots of thinning, you may be experiencing hair loss.
There are many causes for hair loss. Women may notice hair loss after giving birth. People under a lot of stress can see noticeable hair loss. Some diseases and medical treatments can cause hair loss.However, the most common cause of hair loss is a medical condition called hereditary hair loss. About 90 million men and women in Canada and the United States have this type of hair loss, other names for this type of hair loss are:
• Male-pattern baldness
• Female-pattern baldness
• Androgenetic alopecia
Both men and women can suffer from hair loss but the patterns may be different in women than in men. Luckily, most causes of hair loss can be stopped or treated.
There are only 3 FDA approved hair loss treatments available today:
• Low Level Laser Therapy (Hairmax) For Men and Women
In men who develop male pattern baldness the hair loss may begin any time after puberty when blood levels of androgens rise. The first change is usually recession in the temporal areas, which is seen in 96 percent of mature males, including those men not destined to progress to further hair loss.
Hamilton and later Norwood have classified the patterns of male pattern baldness (see illustration below). Although the density of hair in a given pattern of loss tends to diminish with age, there is no way to predict what pattern of hair loss a young man with early male pattern baldness will eventually assume. In general, those who begin losing hair in the second decade are those in whom the hair loss will be the most severe. In some men, initial male-pattern hair loss may be delayed until the late third to fourth decade. It is generally recognized that men in their 20’s have a 20 percent incidence of male pattern baldness, in their 30’s a 30 percent incidence of male pattern baldness, in their 40’s a 40 percent incidence of male pattern baldness, etc. Using these numbers one can see that a male in his 90’s has a 90 percent chance of having some degree of male pattern baldness.
Hamilton first noted that androgens (testosterone, dihydrotestosterone) are necessary for the development of male pattern baldness. The amount of androgens present does not need to be greater than normal for male pattern baldness to occur. If androgens are present in normal amounts and the gene for hair loss is present, male pattern hair loss will occur. Axillary (under arm) and pubic hair are dependent on testosterone for growth. Beard growth and male pattern hair loss are dependent on dihydrotestosterone (DHT). Testosterone is converted to DHT by the enzyme, 5-alpha-reductase. Finasteride (Propecia®) acts by blocking this enzyme and decreasing the amount of DHT. Receptors exist on cells that bind androgens. These receptors have the greatest affinity for DHT followed by testosterone, estrogen, and progesterone. After binding to the receptor, DHT goes into the cell and interacts with the nucleus of the cell altering the production of protein by the DNA in the nucleus of the cell. Ultimately growth of the hair follicle ceases.
The hair growth cycle is affected in that the percentage of hairs in the growth phase (anagen) and the duration of the growth phase diminish resulting in shorter hairs. More hairs are in the resting state (telogen) and these hairs are much more subject to loss with the daily trauma of combing and washing. The hair shafts in male pattern baldness become progressively miniaturized, hair follicle miniaturization illustration) smaller in diameter and length, with time. In men with male pattern baldness all the hairs in an affected area may eventually (but not necessarily) become involved in the process and may with time cover the region with fine (vellus) hair. Pigment (color) production is also terminated with miniaturization so the fine hair becomes lighter in color. The lighter color, miniaturized hairs cause the area to first appear thin. Involved areas in men can completely lose all follicles over time. Male pattern baldness is an inherited condition and the gene can be inherited from either the mother or father’s side. There is a common myth that inheritance is only from the mother’s side. This is not true.
In summary, male pattern hair loss (Androgenetic Alopecia) is an inherited condition manifested when androgens are present in normal amounts. The gene can be inherited from the mother or father’s side. The onset, rate, and severity of hair loss are unpredictable. The severity increases with age and if the condition is present it will be progressive and relentless.
Hair loss in men is likely to occur primarily between late teen-age years and age 40-50, in a generally recognizable "male-pattern" baldness known as androgenetic alopecia. Men with male-pattern hair loss may have an expectation of hair loss if they have male relatives who lost hair in a recognizably male pattern.
Norwood-Hamilton Scale of Male Pattern Baldness
About Hair Loss & Pattern Baldness in Women
Female hair loss occurs in more than one pattern. If you are a woman with loss of scalp hair, you should seek professional advice from a physician or a hair restoration specialist.
In most cases, female hair loss can be effectively treated. If you are a woman who has started to lose scalp hair, you are not alone if:
• You are unpleasantly surprised by the hair loss
• You don’t understand why you are losing hair
The patterns of hair loss in women are not as easily recognizable as those in men. Unlike hair loss in men, female scalp hair loss may commonly begin at any age through 50 or later, may not have any obvious hereditary association, and may not occur in a recognizable "female-pattern alopecia" of diffused thinning over the top of the scalp. A woman who notices the beginning of hair loss may not be sure if the loss is going to be temporary or permanent - for example, if there has been a recent event such as pregnancy or illness that may be associated with temporary hair thinning.
If you are a woman who is worried about loss of scalp hair, you should consult a physician hair restoration specialist for an evaluation and diagnosis. Self-diagnosis is often ineffective. Women tend to have less obvious patterns of hair loss than men, and non-pattern types of hair loss are more frequent in women than in men. Diagnosis of hair loss in a woman should be made by a trained and experienced physician.
In women as in men, the most likely cause of scalp hair loss is androgenetic alopecia - an inherited sensitivity to the effects of androgens (male hormones) on scalp hair follicles. However, women with hair loss due to this cause usually do not develop true baldness in the patterns that occur in men - for example, women rarely develop the "cue-ball" appearance often seen in male-pattern androgenetic alopecia.
Patterns of female androgenetic alopecia can vary considerably in appearance. Patterns that may occur include:
• Diffused thinning of hair over the entire scalp, often with more noticeable thinning toward the back of the scalp.
• Diffused thinning over the entire scalp, with more noticeable thinning toward the front of the scalp but not involving the frontal hairline.
• Diffused thinning over the entire scalp, with more noticeable thinning toward the front of the scalp, involving and sometimes breaching the frontal hairline.
Unlike the case for men, thinning scalp hair in women due to androgenetic alopecia does not uniformly grow smaller in diameter (miniaturize). Women with hair loss due to androgenetic alopecia tend to have miniaturizing hairs of variable diameter over all affected areas of the scalp. While miniaturizing hairs are a feature of androgenetic alopecia, miniaturization may also be associated with other causes and is not in itself a diagnostic feature of androgenetic alopecia. In post-menopausal women, for example, hair may begin to miniaturize and become difficult to style. The precise diagnosis should be made by a physician hair restoration specialist.
It is important to note that female pattern hair loss can begin as early as the late teens to early 20s in women who have experienced early puberty. If left untreated, this hair loss associated with early puberty can progress to more advanced hair loss if it is left untreated.
Non-Pattern Causes of Hair loss in Women
In women more often than in men, hair loss may be due to conditions other than androgenetic alopecia. Some of the most common of these causes are:
Trichotillomania— compulsive hair pulling. Hair loss due to trichotillomania is typically patchy, as compulsive hair pullers tend to concentrate the pulling in selected areas. Hair loss due to this cause cannot be treated effectively until the psychological or emotional reasons for trichotillomania are effectively addressed. Alopecia areata— a possibly autoimmune disorder that causes patchy hair loss that can range from diffuse thinning to extensive areas of baldness with "islands" of retained hair. Medical examination is necessary to establish a diagnosis.
Triangular alopecia— loss of hair in the temporal areas that sometimes begins in childhood. Hair loss may be complete, or a few fine, thin-diameter hairs may remain. The cause of triangular alopecia is not known, but the condition can be treated medically or surgically.
Scarring alopecia— hair loss due to scarring of the scalp area. Scarring alopecia typically involves the top of the scalp and occurs predominantly in women. The condition frequently occurs in African-American women and is believed to be associated with persistent tight braiding or "corn-rowing" of scalp hair. A form of scarring alopecia also may occur in post-menopausal women, associated with inflammation of hair follicles and subsequent scarring.
Telogen effluvium— a common type of hair loss caused when a large percentage of scalp hairs are shifted into "shedding" phase. The causes of telogen effluvium may be hormonal, nutritional, drug-associated, or stress-associated. Loose-anagen syndrome—a condition occurring primarily in fair-haired persons in which scalp hair sits loosely in hair follicles and is easily extracted by combing or pulling. The condition may appear in childhood, and may improve as the person ages. Diagnosis and Treatment
If you are a woman with thinning or lost scalp hair, your first necessary step is to have the condition correctly diagnosed by a physician hair restoration specialist. After a diagnosis is made, the physician will recommend an approach to effective medical or surgical treatment.
Ludwig Classification of Female Pattern Baldness
Olsen EA (ed). Female Pattern Hair loss: Clinical Features and Potential Hormonal Factors. J Amer Acad Dermatol 2001; 45:S-70-S80.
Olsen EA. Hair disorders. In: Freedberg IM et al (eds.) Fitzpatrick’s Dermatology in General Medicine, 5th ed. New York: McGraw-Hill, 1999:729-751.