Generally, male pattern baldness follows a set pattern, starting with a receding hairline which is then followed by the thinning of the hair on the crown and temples. This is the most common type of hair loss in men and in most cases starts around the late 20s or early 30s, by the time most men have entered their late 30s they have experienced some degree of hair loss. In a lot of cases, male pattern baldness leaves a horseshoe shape of hair around the back and sides of the head and can occasionally progress to complete baldness, though it is very rare for it to do so.
It used to be believed that hair loss in men was caused by them having too much testosterone, however this is not the case and the hair follicles become weaker and more sensitive due to a genetic predisposition. Researchers now believe that dihydrotestosterone (DHT), which is a by-product of testosterone, causes the follicles to become sensitive and is the true cause for the hair loss.
With the help of the enzyme type II 5-alpha-reductace, testosterone is converted into DHT which is then stored in the hair follicle’s oil glands. If there is too much DHT in these glands, the hair becomes thinner and grows for a shorter length of time than normal which in turn results in hair loss. DHT acts to suppress and shrink hair follicles, so when the DHT levels become lower, the hair follicles begin to thrive again. Hair follicles that are sensitive to DHT will need to have a prolonged period of exposure for the affected follicle to complete the shrinking process, so it is possible to stop if caught early enough.
Although you may carry the genes for baldness, this doesn’t necessarily mean the you will suffer from hair loss, even if there is a strong family history of it. Everyone is individual and in some cases, the genes responsible may not have been passed on or the expression of the genes could be limited. The way these genes express themselves depends on a number of factors that include your hormones, age and levels of stress.