Hair loss affects about 35 million men and 21 million women in the United States alone. 40% of men have noticeable hair loss by age 35 and 65% by age 60. First you need to understand why hair loss occurs. Your hair loss has little or nothing to do with shampooing, hats, or any other practices. Hair loss is largely genetic.
There are many causes of hair loss in men and women, including disease, nutritional deficiency, hormone imbalance, and stress. By far the most common cause, however, is what is called androgenetic alopecia. Alopecia is simply the medical term for hair loss. Androgenetic refers to the fact that both genetic predispositions to balding and the influence of androgens, or male hormones, play a part in this type of hair loss.
There is a third factor, which is the passage of time, or aging.
So, in order for androgenetic alopecia to occur, there must be:
- genetic propensity for balding
- presence of androgens, or male hormones
- aging time to allow the first two factors to exert their influence on the hair follicles
Both men and women produce “male” hormones. The most common of these are testosterone, androsteinedione, and dihydrotestosterone (DHT). Androgens are produced by the testicles and adrenals in men, and by the ovaries and adrenal glands in women. These hormones are important in both sexes, but occur in different concentrations, being much more predominant in males than in females. This, in part, is responsible for the typical differences between the genders.
The exposure of hair follicles to DHT over a period of time can lead to androgenetic alopecia, male and female pattern baldness, in people who are genetically susceptible to balding. The balding process can occur at any age and move at any rate. It can start in the teen years or late in life, develop rapidly, slowly, or even stabilize.
Other Hair Loss Causes
Alopecia areata (AA) is a recurrent disease, which can cause hair loss in any hair-bearing area. The most common type of alopecia areata presents as round or oval patches of hair loss most noticeably on the scalp or in the eyebrows. The hair usually grows back within six months to one year. Most patients will suffer episodes of hair loss in the same area in the future. Those who develop round or oval areas of hair loss can progress to loss of all scalp hair (alopecia totalis). The cause of alopecia areata is unknown but commonly thought to be an autoimmune disorder in which the body does not recognize the hair follicles and attacks them. Stress and anxiety are frequently blamed by patients as the cause of their hair loss. The most common treatment is with steroids (for example, cortisone) either topically or by injection. The steroid treatment is considered effective if results are seen during the first twelve months of the process. Results can be poor in adults who have seen the effects of the disease for longer periods of time. Minoxidil (Rogaine®) can help to slow down or stop hair loss, but rarely, if ever, is able to regrow hair. In some cases, it can help to grow some hair in the crown, but it will not develop a hairline or fill in an area of recession. Surgical treatment of this disorder is not recommended. If you have questions concerning Alopecia areata, please contact a NuHart physician.
Traction alopecia is caused by chronic traction (pulling) on the hair follicle and is seen most commonly in African-American females associated with tight braiding or cornrow hairstyles. It is generally present along the hairline. Men who attach hairpieces to their existing hair can experience this type of permanent hair loss if the hairpiece is attached in the same location over a long period of time. Trichotillomania is a traction alopecia related to a compulsive disorder caused when patients pull on and pluck hairs, often creating bizarre patterns of hair loss. In long term case of trichotillomania, permanent hair loss can occur.
Hair loss due to scarring of the scalp is called scarring alopecia. Scarring can be due to a variety of causes. Traction alopecia over a period of time may lead to scarring and permanent hair loss. Trichotillomania (compulsive hair-plucking) can cause permanent scalp scarring over time.
Injury to the scalp caused by physical trauma or burns may leave permanent scars and permanent hair loss. Diseases that may cause permanent hair loss due to scalp scarring include (1) the autoimmune conditions lupus erythematosus and scleroderma, and (2) bacterial infections such as folliculitis, fungal infections, and viral infections such as shingles (herpes zoster).
Trichotillomania is the name given to habitual, compulsive plucking of hair from the scalp or other hair-bearing areas of the body. Over time, continual plucking of scalp hair will result in a hairless area-a bald spot. Long term trichotillomania can result in permanent damage to scalp skin and to scarring alopecia. It is not known whether trichotillomania should be classified as a habit or as obsessive-compulsive behavior. In its mildest form, trichotillomania is a habitual plucking of hair while a person reads or watches television. In its more severe forms, trichotillomania has a ritualistic pattern and the hair-plucking may be conducted in front of a mirror. The person with trichotillomania often has guilt feelings about his or her “odd” behavior and will attempt to conceal it.
The cause of triangular alopecia is not known, but the condition can often be treated medically or surgically. The characteristic pattern of hair loss in triangular alopecia is thinning or complete loss of hair in the scalp area around the temples. If hair loss is not complete, the remaining hairs are often “miniaturized”-fine-textured hairs of thin diameter. Triangular alopecia sometimes begins in childhood with unexplained hair loss in the temporal areas of the scalp.
Telogen effluvium is the name given to hair loss that is caused when a large percentage of scalp hair follicles are shifted into the telogen or “shedding phase” of hair growth. See NuHart’s Hair Growth Cycle for more information. The cause of this abnormally timed telogen phase may be hormonal, nutritional, drug-related or associated with stress.
Loose-anagen syndrome occurs most frequently in fair-haired persons. During the anagen (growth) cycle of hair, scalp hairs sit so loosely in the follicles from which they grow that they can be easily extracted by combing or brushing. The condition may appear in childhood and gradually improve or disappear over time.