You are here : Public Resources >> Hair Loss Information >> Stop Hair Loss>> Hair Loss FAQ
1. Are there other types of hair loss?
2. Could you describe the hair growth cycle?
3. How widespread is male pattern hair loss?
4. Is hair loss just a cosmetic issue?
5. What causes androgenetic alopecia/male pattern hair loss?
6. What is androgenetic alopecia/male pattern hair loss?
7. What is the role of 5-alpha reductase in the body?
8. What is the role of testosterone/hormones/androgens in male pattern hair loss?
9. What role does heredity/genetics play in male pattern hair loss?
10.Where is DHT found in the body?
1. Are there other types of hair loss?
Other types of hair loss include:
• Alopecia areata, characterized by circumscribed, nonscarring hair loss in one or more areas of the body, often due to an autoimmune process.
• Telogen effluvium, heavy, short-term shedding of hair due to a disturbance of the hair cycle in which hair prematurely leaves the growing phase (anagen) and enters the resting phase (telogen).
• Traction alopecia, hair loss due to prolonged traction on the hair such as too tight hair styling.
• Anagen effluvium, significant acute hair loss most commonly caused by chemotherapy or radiation.
• Scarring alopecia, localized permanent damage to hair follicles and accompanying hair loss with a variety of causes including fungal infections, inflammation, burns and trauma.
2. Could you describe the hair growth cycle?
All hair follicles are replaced at different rates by the normal process of hair cycling. Hair growth alternates between phases of activity and rest. The growth period, called the anagen phase, lasts for two to six years. During this time, the follicle is long and deep, and produces thick, well-pigmented hair. About 90% of all scalp hairs are in the anagen phase at a given time. The anagen phase is followed by a brief transition period known as the catagen phase, which lasts a few weeks. During this time, the base of the follicle shrivels. The resting period, or telogen phase, lasts for two to four months. In this phase, the follicle withers even further. Following the telogen phase, the next anagen phase begins, and the old hair is dislodged and falls out to make room for a new hair to begin growing in its place.
3. How widespread is male pattern hair loss?
Male pattern hair loss affects approximately 50% of men at some point in their lives. It affects different populations at different rates, probably because of genetics. Up to half of male Caucasians will experience some degree of hair loss by age 50, while other population groups such as Japanese and Chinese men are far less affected.
4. Is hair loss just a cosmetic issue?
Male pattern hair loss can have a serious psychological impact. Studies have shown that hair loss can be associated with low self-esteem, depression, introversion, and feelings of unattractiveness. This is reinforced by attitudes in Western society, which place great value on youthful appearance and attractiveness. Some studies have shown that based on appearance alone, men with hair loss may be seen as less attractive, less assertive, less likable, and less successful than men without hair loss.
Back to the top
5. What causes androgenetic alopecia/male pattern hair loss?
Androgenetic alopecia is an inherited condition caused by a genetically determined sensitivity to the effects of dihydrotestosterone or DHT. DHT is believed to shorten the growth, or anagen, phase of the hair cycle, causing miniaturization of the follicles and producing progressively finer hairs. The production of DHT is regulated by an enzyme called 5-alpha-reductase.
6. What is androgenetic alopecia/male pattern hair loss?
Androgenetic alopecia in men, commonly referred to as male pattern hair loss, is a hereditary condition characterized by a receding hairline and/or hair loss on the top of the head.
Back to the top
7. What is the role of 5-alpha reductase in the body?
It is an enzyme that regulates production of DHT. An enzyme is a protein that acts as a catalyst to speed up a chemical reaction.
Back to the top
8. What is the role of testosterone/hormones/androgens in male pattern hair loss?
Male pattern hair loss or androgenetic alopecia is an androgen-dependent disorder. In genetically susceptible men, dihydrotestosterone (DHT), a potent metabolite of the male androgen testosterone, contributes to male pattern hair loss. The conversion of testosterone to DHT is regulated by the enzyme 5-alpha-reductase. Dihydrotestosterone is believed to shorten the anagen phase of the hair cycle, causing miniaturization of the hair follicles, and producing progressively finer hairs. In MPHL, too many hair follicles go into a "resting period" due to a DHT-induced shift from the anagen phase. Some of the production of healthy new hair is replaced by the growth of fine, almost colorless hair, known as vellus hair. While there is no way of knowing for certain if a man will eventually experience hair loss, researchers do know that heredity influences one's susceptibility to the biochemistry involved in hair loss. It was believed that a man's likelihood of developing MPHL was a trait that was inherited solely through his mother. However, scientists now believe that MPHL can be inherited from either side of a man's family.
9. What role does heredity/genetics play in male pattern hair loss?
Male pattern hair loss occurs in men who are genetically predisposed to be more sensitive to the effects of DHT. Researchers now believe that the condition can be inherited from either side of the family.
10. Where is DHT found in the body?
DHT is found in several tissues in the body including the scalp.