The most common type of hair loss for men is male pattern baldness, which is mainly caused by a genetic trait and hormones. Most usual male pattern baldness is a receding hairline together with hair thinning on the crown and the development of bald spots.
Male pattern baldness has a particular pattern. It begins at the hairline which gradually recedes to form an ‘M’ shape. The existing hair may also become finer and shorter and the hair on the crown also starts to thin. The top of the hairline eventually meets the thinned crown, which creates a horseshoe pattern of hair around the sides of the head.
Inherited (pattern baldness) can affect women but mainly affects men. About a quarter of men are bald or starting to go bald by the time that they are 30 years old. Then by the time that they are 60 about two thirds of men are bald or have a balding pattern.
Male pattern baldness is usually diagnosed based on the appearance and pattern of the hair loss.
A hair grows from, and is held in place by, a hair follicle. Particularly in men these follicles shrink over time and this causes shorter and finer hair. Eventually this can often lead to a very small follicle with no hair inside. In theory hair should start to grow back, however in men who are balding the follicle fails to grow a new hair. This is strange because even though the follicles are small they do remain alive, which means there is the possibility of new growth.