Hair loss of up to 100 hairs a day is normal, and in most people, those hairs grow back. But many men -- and some women -- lose hair as they grow older. You can also lose your hair if you have certain diseases, such as thyroid problems, diabetes, or lupus. If you take certain medicines or have chemotherapy for cancer, you may also lose your hair. Other causes are stress, a low protein diet, a family history, or poor nutrition.
Hair loss (alopecia) can also be the result of heredity. 1 Alopecia areata is an autoimmune disorder characterized by transient, non-scarring hair loss and preservation of the hair follicle. Hair loss can take many forms ranging from loss in well-defined patches to diffuse or total hair loss, which can affect all hair bearing sites. Patchy alopecia affecting the scalp is the most common type. Alopecia areata affects nearly 2% of the general population at some point during their lifetime. 2
Alopecia occurs more often in people with , anxiety, depression, lupus, vitiligo, rheumatoid arthritis, psoriasis as well as other auto-immune diseases. 3. Genetic variants associated with elevated immune response can increase the risk of Alopecia.