Hair loss (alopecia) is an earlier-than-expected or excessive loss of hair. Everyone has some hair loss every day, but some people have a lot of hair loss early in life because it runs in their family (inherited) or because of disease, medicines, aging, injury, stress, or hair care.

The most common type of hair loss is inherited, which is called male-pattern or female-pattern hair loss (androgenetic alopecia). In this type of hair loss, your genes affect how hair grows. Men generally develop bald spots on the forehead area or on the top of the head. In women, hair loss occurs as thinning of the hair on the top of the head. Other types of hair loss can cause hair thinning or clumps of hair to fall out.

Other causes of hair loss include:

• Ringworm of the scalp (tinea capitis), which is common in children.
• Pulling your hair back too tightly, wearing tight braids or ponytails, or using curling irons or dyes.
• Age.

Hair loss is treated with medicines and surgery, including hair transplants. Cosmetic approaches include hairpieces (wigs or toupees) or hair styling techniques, such as combing or dyeing. The specific treatment depends on the cause of the hair loss.