We all know that as we age, our hair gets thinner and we get balder. Is it just our hair follicles that thin out, creating less hair, or do our hair shafts themselves actually thin out too?
This gets kind of complicated. It has to do with your age and your genes and your testosterone levels. Ethnicity, stress, smoking, lack of sleep and some diseases and medications can make a difference.
It has to do with dihydrotestosterone — DHT — which is what you end up with as the hormone testosterone breaks down. DHT brings on the miniaturization of hair follicles so there isn’t as much hair to go around. (Some scientists think Asian men have less DHT in their systems for are less likely to lose hair.)
Thinning hair happens to women, too, when they reach meno
pause, but it is usually evenly distributed as opposed to that receding hair line in men.
This was sort of interesting: Some researchers think going bald may have had evolutionary implications.
The idea is that guys go bald as their testosterone levels drop, which means they spend less time out roostering around and going on hunting trips and more time at home sitting around the campfire telling old-guy lies and finding new ways to make themselves useful to the tribe.
This means they are more available for helping with child care and for passing along tribal lore and skills. Or maybe yelling at the kids to stay off the lawn.Source : http://www.azcentral.com/story/claythompson/2014/10/01/bald-hair-loss-elderly-aging/16541333/