The loss of hair can occur on the scalp or on any part of the body that normally has hair, such as eyebrows or eyelashes. A certain amount of hair loss is normal. The average person normally sheds 50 to 100 hairs every day. The hair shed daily is not necessarily permanent hair loss. Most of the hair we shed grows back.
All hairs have a life expectancy of three to six years.
At any given time, some of our hair is growing, some is done growing and in the resting stage, and some is in the falling-out stage. Everyone sheds hair at about the same rate, but there are some people, through genetics, who have fewer new hairs that grow to replace those that shed. Pattern baldness or permanent hair loss is simply the result of genetic programming. Increased hair shedding, or temporary hair loss can be caused by a host of different reasons. Some of these reasons include poor nutrition and diet, genes, hormones, age, medications such as chemotherapy, radiation treatment, infections, stress, chemicals used for certain hairstyles, and rapid weight loss.