Discuss some of the causes of infertility in men.

Answers will vary. A low sperm count-or lack of sperm-is the most common infertility problem in men. Men's fertility problems have a variety of causes: genetic factors, environmental poisons, diabetes, sexually transmitted infections (STIs), overheating of the testes (which happens now and then among athletes, such as long-distance runners), pressure (as from using narrow bicycle seats), aging, certain prescription and illicit drugs, and obesity (American Fertility Association, 2014). Sometimes the sperm count is adequate, but other factors such as prostate or hormonal problems deform sperm or deprive them of their motility. Motility can also be impaired by the scar tissue from infections, such as STIs.