Baldness or hair loss Most people lose about 50 to 100 head hairs a day which is replaced naturally. This amount of hair loss is totally normal and no cause for worry. Hair loss during adolescence can mean a person may be sick or just not eating right. Some medications or medical treatments, like chemotherapy treatment for cancer, hormonal problems and certain infections also cause hair loss. “Common baldness” usually means male-pattern baldness or permanent-pattern baldness, also called androgenetic alopecia and is the most common cause of hair loss in men.