Symptoms

Hair loss can occur as thinning, in which you may not notice hair falling out, or as shedding, in which clumps of hair fall out.

In the most common type of hair loss, inherited hair loss (androgenetic alopecia), men tend to lose hair on the front hairline and forehead and on top of the head. Eventually, only hair around the ears, the sides, and the back of the head remains. Women with this condition typically have gradual thinning throughout the scalp, but mostly on the top of the head.

Other causes of hair loss may also show distinct patterns. For example, conditions such as trichotillomania (compulsively pulling at the hair) or alopecia areata (in which the immune system attacks hair follicles) result in obvious patches of hair loss, while stress and some medicines result in clumps of hair falling out.

Because hair is an important part of appearance, hair loss can also result in loss of self-esteem and feeling unattractive, especially in women and teens.

What Happens

What happens in hair loss depends on its cause.

Inherited hair loss

Inherited hair loss (androgenetic alopecia) is also called male-pattern hair loss or female-pattern hair loss. About half the population have some hair loss by about 50 years of age. Men may start losing hair between the ages of 15 and 25, and women are more likely to start losing hair between the ages of 25 and 30, or in some cases, after menopause.¹

Men tend to lose hair on the front hairline and temples and on top of the head. Eventually, they may go completely bald.

Women generally lose less hair than men, but they have a similar pattern of hair loss. Women may have slight, moderate, or even severe hair loss, but they don't usually lose all their hair.

For both men and women, inherited hair loss must be treated early for hair to regrow.

Other causes of hair loss

Alopecia areata is hair loss caused when the immune system attacks hair follicles, where hair growth begins. It usually starts with one or more small, round, smooth bald patches on the scalp and can progress to total scalp hair loss or complete body hair loss. It often begins in childhood. The hair usually grows back within 1 year. But hair loss in alopecia areata often comes and goes—the hair will grow back over several months in one area but will fall out in another area.

Hair loss also may be caused by stress, disease, medicines or medical treatments. In these cases, clumps of hair may fall out. But after the cause is stopped, the hair usually grows back, although sometimes treatment may be needed.

Treatment to regrow hair does not work for everyone. If your hair loss is inherited, treatment may not permanently restore your hair. If your hair loss is caused by medicine, stress, or damage, hair often grows back after the cause is removed, although sometimes you will need treatment.

For both men and women, hair thinning and baldness increase the risk of sunburn and skin cancer on the scalp. When in the sun, it is important to wear a hat or use a sunscreen with an SPF of 30 or more to prevent sun damage to the scalp.