Why body hair never grows as long as the hair on your head
Have you ever wondered why the hair on your arms and legs never grows as long as the hair on your head? Why you’re not covered in fuzz akin to the lustrous mane that crowns your scalp? Unsurprisingly, there’s a scientific answer; it’s all about genetics.
Hair growth has a number of different phases; how long your hair eventually gets is determined by the first, the anagen phase. If this phase is short, so is your hair – the longer it goes on, the longer the hair. The length of this phase is mostly in your genes, but can also be influenced by hormones or even stress.
The next phase – catagen – cuts the hair root off from its blood supply and stops it growing. This phase usually lasts about three weeks, and leaves the follicle in a ‘resting’ state with the hair completely dead. This makes them easy to pull out (hair that comes out in your brush/while you’re washing is in this phase).
Arm and leg hair, put simply, has a much short anagen phase than hair on your head – hence, why it doesn’t get to the point where you have to braid it to keep things tidy. The reason some people’s body hair is longer than others is also down to the length of their anagen phase; they’re hairier because their genes say they are. Incidentally, for most people the anagen phase for head-hair is anywhere between 2 and 7 years; for arms, legs etc. it’s usually only 30-45 days. Usually, about 90% of all the hair on your body is in the anagen phase, 2% in the catagen phase and the rest in the telogen phase, although extreme stress can send a whole load of follicles rushing to the final phase – this leads to a lot of hair falling out all at once, which sounds great if you’re bored of shaving your legs, but unfortunately also involves waving goodbye to your head hair into the bargain.