The medical term for hair loss is alopecia. Pattern baldness (androgenetic alopecia), the most common type of alopecia, affects roughly one-third of men and women. It's typically permanent. Other types of alopecia are temporary, including alopecia areata. It can involve hair loss on your scalp or other parts of your body.
Permanent hair loss
* Male-pattern baldness (androgenetic alopecia). For men, pattern baldness can begin early, even in the teens or early 20s. It's typically characterized by a receding hairline at the temples and balding at the top of the head. The end result may be partial or complete baldness.
* Female-pattern baldness (androgenetic alopecia). Women with permanent hair loss usually have hair loss limited to thinning at the front, sides or crown. Women usually maintain their front hairline and rarely experience complete baldness.
* Cicatricial (scarring) alopecia. This rare condition occurs when inflammation damages and scars hair follicles, causing permanent hair loss. Sometimes the patchy hair loss is associated with itching or pain.
Temporary hair loss
* Alopecia areata. Hair loss usually occurs in small, round, smooth patches about the size of a quarter. Usually the disease doesn't extend beyond a few bare patches on the scalp, but it can cause patchy hair loss on any area that has hair, including eyebrows, eyelashes and beard. In rare cases, it can progress to cause hair loss over the entire body. If the hair loss includes your entire scalp, the condition is called alopecia totalis. If it involves your whole body, it's called alopecia universalis. Soreness and itching may precede the hair loss, but symptoms are often minimal.
* Telogen effluvium. This type of temporary hair loss occurs suddenly, most often after a significant illness or major life stress. Handfuls of hair may come out when combing or washing your hair or may fall out after gentle tugging. This type of hair loss usually causes overall hair thinning and not bald patches.
* Traction alopecia. Bald patches can occur if you regularly wear certain hairstyles, such as pigtails, braids or cornrows, or if you use tight rollers. Hair loss typically occurs between the rows or at the part where hair is pulled tightly.
* Anagen effluvium. In this type of hair loss, actively growing hairs in the anagen state are affected most often by chemotherapeutic drugs given to fight cancer or lymphoma. Hair loss starts soon after beginning therapy and is more extensive than in the telogen effluvium state. In the weeks after the therapy has been completed, the hair cycles re-establish themselves, although the hair may not return as thickly as before chemotherapy.
When to see a doctor
Talk to your doctor if you notice sudden or patchy hair loss or more than usual hair loss when combing or washing your hair. Sudden hair loss can signal an underlying medical condition and may require medical treatment.
No cure is available for permanent hair loss or baldness. However, you can talk to your doctor about medical treatments to slow the rate of hair loss or to hide hair loss.