Male Pattern Baldness

Male pattern baldness affects over half of men to some extent over the age of 50 and most men at some stage in their lives. Most affected men do not wish to have any treatment. If required, treatment can usually prevent further hair loss and often cause hair regrowth.

Male pattern baldness is the common type of hair loss that develops in most men at some stage. The condition is sometimes called androgenetic alopecia. It usually takes 15-25 years to go bald. However, some men go bald in fewer than five years.

Typically, at first the hair begins to thin (recede) at the sides (temples). At the same time, the hair usually becomes thin on the top of the head. A bald patch gradually develops in the middle of the scalp. The receding sides and the bald patch on the top (the crown) gradually enlarge and join together, leaving a patch at the front. The patch at the front eventually thins as well.

A rim of hair is often left around the back and sides of the scalp. In some men, this rim of hair also thins and goes to leave a completely bald scalp.

Who gets male pattern baldness?

Nearly all men have some baldness by the time they are in their 60s. However, the age the hair loss starts is variable. About three in ten 30 year-olds and half of 50 year-olds are quite bald. Some women also develop a similar type of hair loss, mainly at the crown. Baldness in women is much more common after the menopause. About 13 in a 100 women have some baldness before the menopause, rising to 75 in a 100 over the age of 65.

What causes male pattern baldness?

Hair is made in hair follicles which are like tiny pouches just under the skin surface. A hair normally grows from each follicle for about three years. It is then shed and a new hair grows from the follicle. This cycle of hair growth, shedding and new growth goes on throughout life. The following is thought to occur in men as they gradually become bald:

Affected hair follicles on the scalp gradually become smaller than normal.

As the follicle shrinks, each new hair is thinner than the previous one.

Before falling out, each new hair grows for much less time than the normal three years or so.

Eventually, all that remains is a much smaller hair follicle and a thin stump of hair that does not grow out to the skin surface.

Male hormones are involved in causing these changes. The level of the main male hormone, testosterone, is normal in men with baldness. Hair follicles convert testosterone into another hormone called dihydrotestosterone. For reasons that are not clear, affected hair follicles become more sensitive to dihydrotestosterone, which causes the hair follicles to shrink. It is also not clear why different hair follicles are affected at different times to make the balding process gradual.

The condition is hereditary (genetic); the location of the gene was identified in 2008.

It is also not clear why only scalp hairs are affected and not other areas such as the beard or armpits.

Are there any complications from male pattern baldness?

Although male pattern baldness is a common and harmless condition, it can be linked to metabolic syndrome (the combination of obesity, diabetes, raised blood pressure and raised choleterol), resulting in an increased risk of heart disease. This link is most often seen in men who develop baldness at a relatively young age.

Women with male pattern baldness should be checked for causes of raised male hormone levels, such as polycystic ovary syndrome (a condition in which cysts develop in the ovaries).