Partial and complete hair loss is called alopecia. Hair loss usually develops gradually and may be patchy or all over (diffuse). You lose roughly 100 hairs from your head every day. The average scalp contains about 100,000 hairs. The normal cycle of hair growth lasts for 2 to 3 years. Each hair grows approximately 1 centimeter per month during this phase. About 90 percent of the hair on your scalp is growing at any one time. About 10 percent of the hair on your scalp, at any one time, is in a resting phase. After 3 to 4 months, the resting hair falls out and new hair starts to grow in its place.
Alternative Names of hair loss: Loss of hair; Alopecia; Baldness; Telogen effluvium
Cause:
A number of causes can contribute to excessive hair loss. For example,
Ø Illness for about 3 to 4 months or
Ø A major surgery, one may suddenly lose a large amount of hair. This hair loss is related to the stress of the illness and is temporary.
Ø Also_ Hormonal imbalance may cause hair loss. Over activating or under activating of thyroid gland may cause hair fall out. This hair loss usually can be helped by treatment thyroid disease. Hair loss may occur if male or female hormones, known as androgens and estrogens, are out of balance. Correcting the hormone imbalance may stop your hair loss.
Ø Another cause may arise when a woman after they have a baby for about 3 months. This loss is also related to hormones. During pregnancy, high levels of certain hormones cause the body to hair fall.
Ø Some medicines can cause hair loss. This type of hair loss improves when you stop taking the medicine. Medicines that can cause hair loss include blood anticoagulants, medicines used for gout, high blood pressure or heart problems, vitamin A (if over dose), birth control pills and antidepressants.
Ø Certain infections can cause hair loss. Fungal infections of the scalp can cause hair loss in children. The infection is easily treated with antifungal medicines.
Ø Finally, hair loss may occur as a part of some disease, such as lupus or diabetes also typhoid.