Alopecia means hair loss or baldness. Hair loss occurs for many reasons, frompulling hair out to having it killed off by cancer chemotherapy. Some causesare considered natural, while others signal health problems. Some conditionsare confined to the scalp. Others reflect disease throughout the body.
Often conditions affecting the skin of the scalp result in hair loss. The first clue to the specific cause is the pattern of hair loss, whether it be complete baldness, thinning, or patchy bald spots. Another factor is the condition of the hair and the scalp beneath it. Sometimes only the hair is affected,while sometimes the skin is diseased as well.
Male pattern baldness is considered normal in adult men. Hair loss occurs across the top and front of the head, while the scalp remains healthy. Fungal infections of the scalp usually cause patchy hair loss. The fungus, similar tothe ones that cause athlete's foot or ringworm, often glows under ultravioletlight.
Hair loss may also be caused by mental disorders or from unidentified causes.Complete hair loss is a common result of cancer chemotherapy, due to the toxicity of the drugs used.
Diseases often affect hair growth either selectively or by altering the skinof the scalp. For example, hyperthyroidism (too much thyroid hormone) causeshair to become thin and fine. Hypothyroidism (too little thyroid hormone) thickens both hair and skin.
Dermatologists are skilled in diagnosing the cause of hair loss by sight alone, but also perform a skin biopsy, removing a tiny bit of skin using a localanesthetic so that it can examined under a microscope. Successful treatment of underlying causes is most likely to restore hair growth. Two drugs, minoxidil (Rogaine) and finasteride (Proscar), promote hair growth in a significantminority of patients. When used continuously for long periods of time, minoxidil produces satisfactory results in about one quarter of patients with malepattern baldness and as many as half the patients whose hair loss is caused by unknown causes. Both drugs have so far proved to be quite safe when used for this purpose.
Over the past few decades there have appeared a multitude of hair replacementmethods performed by both physicians and non-physicians. They range from simply weaving someone else's hair in with the remains of the client's own to surgically transplanting thousands of hair follicles one at a time.
How successful the outcome of treating baldness is varies with the cause. Itis easier to lose hair than to re-grow it. Even when it returns, it is oftenthin and less attractive than the original crop. However many people who losehair as the result of chemotherapy or fungal infection are able to grow backnormal hair once they stop chemotherapy or are treated for the fungal infection.