Male pattern baldness is the most common type of hair loss for men. Indeed, it will affect virtually every man at some point in their lives, though the extent and the speed at which it takes hold can vary markedly.
As the name suggests, the condition tends to follow a pattern. At the beginning, hair will start to recede from the front of the head, exposing the temples, with the hair on the top of the head then starting to thin. Eventually, whether it's after five or 25 years, the receding front hairline and the bald spot on the scalp will enlarge and join together.
There is no predetermined age for the onset of male pattern baldness. While some men may retain all their hair until their 60s, others may start to thin in their 20s or even their late teens.
Male pattern baldness is the result of the hair follicles on the head becoming too sensitive and so ending the cycle of hairs growing again after being shed. More specifically, the condition occurs when dihydrotestosterone (DHT) is produced by the male hormone testosterone, with this making individual follicles shrink and eventually shut down.
Given that male pattern baldness is caused by hormones, and in particular by testosterone, many people take baldness as a sign of enhanced virility, though the NHS advises that this is not the case - that is, bald men don't have more testosterone, they simply have more-sensitive hair follicles.
One myth that does ring true is that baldness passes down through generations. Male pattern baldness is hereditary and can be passed down to women as well as men.
Male pattern baldness is, on its own, harmless, with the baldness process completely pain-free.
That said, for many men, baldness can be distressing, especially if it sets in early on in life, for instance in their 20s or 30s. Indeed, male pattern baldness can trigger attacks of low self-esteem, anxiety and even depression, and for this reason, a significant proportion of men try and fight back against the condition using whatever treatment they can.
At the same time, a number of studies have linked male pattern baldness with a range of other health conditions. In particular, research has uncovered possible links between baldness and an increased risk of heart disease, while in many cases the loss of hair may be an indicator of raised cholesterol or high blood pressure.
A significant proportion of men opt against treating male pattern baldness, instead simply resigning themselves to going bald and accepting it as a fact of life. Again, however, for many men, losing their hair can lead to a loss in self-confidence and may also cause depression. As such, a number of potential treatments are currently on the market.
In terms of medication, specialist products available in high street chemists have been shown to at least slow hair loss and even promote re-growth in around two in three men. However, these treatments can be costly (they are not available on the NHS), particularly since they need to be taken every day without fail in order to work. Additionally, a minority of men report a loss of libido when taking hair loss medication.
Other potential solutions can include the wearing of a wig or even the transplanting of hair from other parts of the body onto the head.