Topic Overview

Hair loss, including thinning and breaking, is the most common scalp problem. Most people lose from 50 to 100 hairs per day.

Hair gradually thins as people age, although not everyone is affected to the same degree. Hereditary thinning or balding (androgenetic alopecia) is the most common cause of thinning hair. You can inherit this from either your mother's or father's side of the family. Women with this trait develop thinning hair, while men may become completely bald. The condition can start in the teens, 20s, or 30s.

Babies often lose their fine baby hair, which is then replaced by mature hair. Because of changes in hormones, women often lose hair for 1 to 6 months after childbirth or after breast-feeding is completed.

Other possible causes for excessive hair loss, thinning, or breakage include:

• Damage to the hair from hair care products, such as dyes and permanents, and from hot rollers, curling irons, or hair dryers.
• Hair-pulling or hair-twisting habits. Trichotillomania is a mental health problem in which a person pulls out his or her own hair, usually from the head, eyelashes, and eyebrows.
• Side effects of medications or medical treatments, such as chemotherapy or radiation therapy.
• Recent surgery, high fever, or emotional stress. You may have a lot of hair loss 4 weeks to 3 months after severe physical or emotional stress. This type of hair loss usually stops within a few months.
• Diseases, such as lupus and hyperthyroidism.
• Heavy metal poisoning, such as thallium or arsenic poisoning.
• Poor nutrition, especially lack of protein or iron in the diet.
• Damage to the hair follicles from burns or other injuries.

Some hair loss problems will correct themselves. Treatment for hair loss depends on the cause of the hair loss.