The average person loses between 50 and 100 hairs per day without noticing; however, when hair falls out more rapidly we use the term hair loss. Hair loss can affect only the scalp or the entire body. It is not usually something to cause concern but can sometimes indicate an undiagnosed medical condition. It is therefore important to check with a doctor if you are concerned.
Hair loss can happen suddenly or gradually, depending on what is causing it. Some types are hair loss are permanent while others are temporary. Most commonly, age causes the hair to gradually thin on top of the head, while additionally receding in males. Circular or patchy bald spots may occur with age or due to skin disorders such as alopecia. Physical or emotional trauma can cause hair to loosen and suddenly fall out. This usually results in the hair thinning rather than causing bald patches. Full-body hair loss can occur following medical treatments such as chemotherapy.
Risk factors which increase the risk of hair loss include a family history of baldness, age, significant weight loss, medical conditions such as diabetes, and stress.