Through an unclear set of neurochemical events, the hair follicle gets the message that the body needs all the resources it has for more important things than hair, like childbirth and nursing. It usually affects small, circular patches of the scalp in no apparent pattern. Although hair loss can occur with the stress of any illness, it is also a particular symptom of many different diseases. Most differ in the pattern of hair loss, and almost never resemble Male Pattern Baldness. It's also important to recognize that hair loss is seldom the first and only presentation of these diseases.
Most hair comes back when the disease goes away or is adequately treated.
Traction alopecia is hair loss due to excessive and chronic pulling, or traction, on hair. It commonly occurs in people who braid or knot their hair. There is pronounced traction alopecia in the beard area of this Sikh man. In the Sikh religion, men do not cut scalp or beard hair. The beard hairs are pulled straight and then twisted and tightly knotted.