The most frequent cause of hair loss is an inherited hormonal disorder of the hair-producing cells (hair follicles). Hair loss generally occurs slowly and without being noticed. Usually, there are other bald family members. Hair loss is locally limited to determined areas. This fact leads to typical hair loss on the hair line on the forehead, the parting of the hair and at the hair crowns of men. Hair roots from the hair line of the back of the head are not affected by genetic information. That is why hair extracted from this area does not fall off once it is in the transplanted area (dominance of donor). Up to 70% of men and 50% of women are affected by inherited hair loss. Hair loss in women is different than in men. It often affects parting or occurs on the whole scalp. In this case, hair transplantation is not recommended.