Each hair sits in a cavity in the skin called a follicle. Over time the follicle can shrink causing the hair to become shorter and finer. Ordinarily, the hair should grow back but in men who are balding the very small follicle ceases to grow any hair. The cause of baldness is not well understood, but is thought to be related to the genes and male sex hormones of the individual.
Update Date 5/15/2013
Updated by: Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.