Why Does The Hair On My Head Grow Longer Than The Hair On My Body?

Xie Qiuping set the Guinness World Record for longest hair on May 8th, 2004 when her hair was measured at 18 ft 5.54 in (5.627 m).

Kenzo Tsuji holds the Guinness World Record for longest arm hair at 7.44 in (18.90 cm).

Both have far more hair than any of us will ever have, but it raises the question: why does the hair on our heads grow much longer than the hair on our bodies? Let’s find out in today’s edition of Wonder Why Wednesday…

Why Does The Hair On My Head Grow Longer Than The Hair On My Body?

To learn why our head hair is longer than our arm hair we first must understand how hair growth works.

The Washington Post explains it this way:

All hair and fur grows in cycles. In the anagen phase, a protein root down in your hair follicle starts accumulating cells that form into a rope-like structure we know as hair. Your scalp’s blood supply feeds the follicle and allows it to divide into more cells. As long as the anagen phase lasts, your hair will grow longer and longer, unless you cut or break it, at a rate of about a half-inch each month.”

The growth cycle for head hair varies for each of us, but it usually lasts a few years. At the end of the cycle the follicle slowly withers and the hair new cells no longer get fed.

The reason our body hair is much shorter is because their growth cycle is much shorter. The hair on our arms, legs and other parts of our body may have a cycle that lasts just a few weeks, rather than years. In less than a month, our body signals to the hair follicle that its time is done and the dead strand either falls off or is moved out by a new one as the new anagen phase begins.