Women's skin has twice as many nerve fibers as men's skin. A body of research has yet to yield definitive answers, says pain researcher April Hazard Vallerand, PhD, RN of Detroit's Wayne State University College of Nursing. "It does look like females have some differences in pain in some areas," said Vallerand. "Women can detect heat more easily. But women also acknowledge pain more frequently. What underlies all this is that women are more willing to discuss their symptoms in the first place."