15 Ways Women Are Tougher, Luckier, and Smarter Than Men

We're at Far Lower Risk for Blood Disease

Hemophilia is a disorder that prevents blood from clotting normally, and can lead to excessive and internal bleeding. It's caused by a gene defect located on the X chromosome. Women will not develop the disease unless both chromosomes are affected—and that's extremely rare. Because men only have one X chromosome, they are much more susceptible to hemophilia.