What is Alopecia (Hair Loss)


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In the past few years, dermatologists have seen an increasing number of adults coming for consultations because of hair loss. In most of these cases, examination of the scalp and a careful history seeking the common diseases that cause hair loss does not show any abnormality. These hair loss problems usually are the result of an alteration in the rate of hair production as controlled by the natural cycle that the scalp follows in growing hair, or a hereditary natural decrease in the amount of hair a person is to have with aging and hormonal changes, or an increased hair fall related to an improper grooming technique which causes excessive pulling or traction of the hair.

Dermatologists believe that these types of hair loss were always around but that the increasing emphasis on cosmetic appearance in our society makes people more aware of them. The availability of dermatologic consultation and the educational emphasis on medical examination and treatment for all diseases is bringing more patients with alopecia to dermatologists.

Where there is no specific infectious or inflammatory scalp disease known to cause hair loss, there is no treatment that will cause hair to grow unless the body intends to do it on its own. Hereditary pattern hair loss in not benefitted by any non-surgical treatment whatsoever. Dandruff and seborrheic dermatitis of the scalp do not cause baldness. Many persons have spent large sums of money on worthless special creams, shampoos and treatments, have bought special combs, brushes and other apparatus only to learn that it was all a waste.

HOW HUMAN HAIR GROWS: THE HAIR CYCLE To best understand the problems of hair loss, you must first understand how hair grows. Hair does not grow like grass. If it did, you would expect every hair to be growing at the same rate on your scalp. At the end of a even period of time all the hairs would end their life span together and fall out together. This would leave you totally bald until a new crop began to grow. The hair growth cycle, which is affected by many things, prevents these episodes of total baldness. Every hair is growing at a different rate on your scalp. At any one time about 80% of the hairs are in a growing phase. About 15% have stopped growing and are waiting to enter the stage when they can fall. About 5% of the hairs are available to fall at any given point in time. You can normally lose up to 500 hairs per day. Once a hair falls, the body immediately gets busy in growing a new hair. There is nothing you can rub on the scalp or take as a medicine that will make this new hair grow out faster if the body wants to grow a new hair there.

HAIR LOSS DUE TO EFFECTS ON THE HAIR CYCLE Many circumstances affect the hair cycle so that at a given time more than 5% of the hairs are available to fall out. These conditions must be tolerated by the patient until natural factors correct the hair cycle or stabilize it at a new percentage. Factors such as heredity, age, hormones, and shocks to the system such as fever, infection, pregnancy, and medications, such as birth control pills, all affect this system.

Pregnancy and birth control pills act in a similar way to keep a large number of hairs, through hormonal support, in a growth phase for a long period of time. When the pregnancy ends or the pills are stopped or the body escapes from the effect of the pill on the hair cycle, a large number of hairs which should have fallen out a long time ago are now going to fall out over a short period of time until the hair cycle recovers. This condition will last a short period of time until the hair cycle "normalizes" and all of the hairs are lost that must fall - about six months. Treatments here are of no value since the body will correct the condition itself.

GROOMING TECHNIQUES AND HAIR LOSS Tight roller curlers, tightly braided hair styles and teasing are a frequent cause of hair loss as a result of constant low grade traction or pulling on the hair. This removes the 5% of the hairs destined to fall at a faster rate and may even remove some of the older resting hairs. Where this is the condition, the recommendation will be to stop this grooming style completely and try a different hair style that does not require this. In all cases of hair loss, this should be avoided in order to hold in the hairs you have for as long as possible.


Common "male pattern" baldness results from the combination of adequate androgen (gonad derived hormone) levels and the appropriate genetic background. The term androgenetic alopecia is appropriate and makes reference to both requisite factors: androgens and a genetic predisposition. Both men and women are affected by this process but the patterns of hair loss are quite distinct. In males hair loss usually occurs in the frontotemporal and vertex (top) areas. In females, it tends to be more diffuse and generalized.

Androgenetic alopecia results from transformation of terminal hair follicles into vellus-like (immature) follicles, which then become atrophic and waste away. The progression is gradual and the process may become noticeable after puberty in either sex.

Topical treatments such as minoxidil (Rogaine) have been shown to slow the progression of hair loss as well as cause hair regrowth. The mechanism is not completely understood but may be related to the effect of minoxidil directly stimulating the hair follicles. Recently, oral therapy with finasteride (Propecia) has been shown to be effective at halting hair loss and causing hair regrowth. The mechansim of this medication is directly related to the inhibition of production of androgens and thus dimished stimulation of transformation of terminal hair follicles to vellus hair follicles.