Reasons for hair loss

A variety of conditions can cause hair loss, including:

Hormonal changes: Hormonal changes and imbalances can cause temporary hair loss. This could be due to pregnancy, childbirth or the onset of menopause. Hormone levels are also affected by the thyroid gland, so thyroid problems may cause hair loss.

Patchy hair loss: This type of nonscarring hair loss is called alopecia areata (al-o-PEE-she-uh ar-e-A-tuh). It occurs when the body's immune system attacks hair follicles - causing sudden hair loss that leaves smooth, roundish bald patches on the skin.

Scalp infections: Infections, such as ringworm, can invade the hair and skin of your scalp, leading to scaly patches and hair loss. Once infections are treated, hair generally grows back.

Other skin disorders: Diseases that cause scarring alopecia may result in permanent loss at the scarred areas. These conditions include lichen planus, some types of lupus and sarcoidosis.

Hair-pulling disorder: This condition, also called trichotillomania (trik-o-til-o-MAY-nee-uh), causes people to have an irresistible urge to pull out their hair, whether it's from the scalp, the eyebrows or other areas of the body.