Hair loss is a very common condition and affects most people at some time in their lives.
Our hair is made up of a protein called ‘keratin’ that is produced in hair follicles in the outer layer of skin. As follicles produce new hair cells, old cells are being pushed out through the surface of the skin at the rate of about six inches a year.
The average adult head has about 100,000 to 150,000 hairs and loses up to 100 of them a day.
At any one time, about 90% of the hair on a person’s scalp is growing. Each follicle has its own life cycle that can be influenced by age, disease, and a wide variety of other factors. This life cycle is divided into three phases:
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Anagen — active hair growth that lasts between two to six years
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Catagen — transitional hair growth that lasts two to three weeks
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Telogen — resting phase that lasts about two to three months; at the end of the resting phase the hair is shed and a new hair replaces it and the growing cycle starts again.
Causes of hair loss:
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Hormones, such as abnormal levels of androgens (male hormones normally produced by both men and women)
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Genes, from both male and female parents, may influence a person’s predisposition to male or female pattern baldness.
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Stress, illness, and childbirth can cause temporary hair loss.
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Drugs, including chemotherapy drugs used in cancer treatment, blood thinners, beta-adrenergic blockers used to control blood pressure, and birth control pills, can cause temporary hair loss.
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Burns, injuries, and X-rays can cause temporary hair loss.
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Alopecia areata; Autoimmune disease which causes destruction of hair follicles in localized areas of skin
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Cosmetic procedures, such as shampooing too often, perms, bleaching, and dyeing hair can contribute to overall hair thinning by making hair weak and brittle. Tight braiding, using rollers or hot curlers, and running hair picks through tight curls can also damage and break hair. However, these procedures don’t cause baldness.
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Medical conditions. Thyroid disease, lupus, diabetes, iron deficiency, eating disorders, and anemia can cause hair loss.
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Diet. A low-protein diet or severely calorie-restricted diet can also cause temporary hair loss.