Alopecia areata affects approximately 1.7 percent of the population overall and over 6 million people in the US alone.
Alopecia areata is characterized by the formation of well defined hairless round patches, which vary in size. Some people may lose more or all their hair. The cause that provoke the condition are unknown. Alopecia areata is considered an autoimmune disease, in which the immune system, which is designed to protect the body from foreign invader such as viruses and bacteria mistakenly attacks the hair follicles which is the structure from which hairs grow.
Anyone can have alopecia areata, it often begins in childhood and may happen more than once during your lifetime. Living with hair loss can be hard, however this form of Alopecia is generally reversible even if you have lost all of your hair.