Alopecia describes hair loss, which may occur in men, women, or children. Hair loss may eventually lead to excessive hair loss, called baldness. Hair loss and baldness can occur for a number of different reasons.
It is normal for some hair to fall out each day. It is estimated that adults lose 50-100 hairs each day because hair only lives two to six years. Once a hair is shed, a new hair grows to replace it. In general, hair grows about one-half inch each month. Hair growth may be less noticeable in patients with curly hair. As individuals age, most people experience hair thinning or loss.
There are two main types of hair loss: alopecia areata and androgenetica alopecia.
Alopecia areata is an immune system disorder. Normally, the immune system helps protect the body against disease and infection. However, the immune system in patients with alopecia areata mistakes the openings in the skin where hair grows, called hair follicles, as harmful invaders. As a result, the immune system launches an attack against the hair follicles, causing hair loss.
Patients with alopecia areata typically receive drugs called corticosteroids for the rest of their lives. These drugs help reduce the body's immune response, limiting the amount of hair follicles that are attacked.
Androgenetica alopecia is an inherited form of baldness. This means the condition is passed down through families. An estimated 60% of patients with androgenetica alopecia are male. When the condition occurs in men, it is called male-pattern hair loss.
Although there is currently no cure for androgenetica alopecia, there are several medical treatments available to replace lost hair. Individuals may also choose non-medical treatments, such as wigs or hairpieces, to replace lost hair. Some patients with androgenetica alopecia prefer to let the hair loss run its course.
In addition, several other factors may lead to temporary hair loss, including medications and medical treatments, poor nutrition, infancy, hair treatments, infections, and illnesses.

Related Terms

Alopecia areata, androgenetic, androgenetica alopecia, autoantibodies, autoimmune, autoimmune disorder, autoimmunity, bald, balding, chemotherapy, corticosteroids, dandruff, genetic, FANA, fluorescent antinuclear antibody test, follicle, hair, hair follicle, hair replacement, hair restoration, immune, immune defense system, immune system, immune reaction, immune response, inherited, male-pattern baldness, radiation therapy.