Androgenetic Alopecia or pattern alopecia as it is sometimes called and also known as Male Pattern Baldness (due to the largely male population that suffers from it) is the progressive miniaturization or thinning of hair as a result of DHT blocking nutrients required by the hair follicle for natural healthy growth. Without proper nutrition, the resting stages of the hair get longer and the growing phases get shorter.
DHT levels have been shown to increase as testosterone levels decrease as part of Andropause (or male menopause). Like Menopause for women, the timing for onset of Andropause in men is passed down to a man from his mother. So to see the pattern your hair loss will take and the age you will start to bald, you should look to your maternal grandfather (or your mother if you are a woman).
Full andropause (and menopause) generally commences between the ages of 40 and 55, however symptoms such as thinning hair have been reported in men as young as their very early 20’s.
As a result of the onset of Andropause and the associated increase in DHT levels, 50% of men will lose 50% of their hair by the age of 50. Only 50% of the hair on a man’s head is permanent.
The top 50% of the hair on your head is susceptible to the impact of DHT and therefore will lose its hair. This is why you always see balding men start to lose their hair with a receding hair line, then thinning on top and eventually they end up with hair only around the back of the head and just above the ears.
As your DHT levels increase and begin to affect you it, will initially start to stunt the hairs growth. Your hair will start to thin, will grow at a slower rate and the hair follicles in the affected areas will eventually die. Once this has happened there is nothing that can be done to revive or regrow that hair and the only option for hair replacement is a surgical one. By the time your scalp is shiny it’s too late.
To break it down, you can think of your hair as a lawn of grass and DHT as the weeds which prevent the earth’s nutrients and water from getting to the grass and strangling it. Gradually the grass will grow thinner and stunted until eventually it browns and dies. Once the grass in a certain area is dead it cannot be regrown unless other grass is dug up from another spot and replanted in the dead area. The only way to prevent this is to pull out the weeds before the grass has died and then to provide additional nutrients to assist the regrowth faster and fuller than could occur naturally (seeing as the remaining grass is already stunted and weak).