- Genetic diseases can affect sperm count. According to babyhopes.com, cystic fibrosis patients sometimes experience this condition, as do Kleinefelter syndrome and Kartagener syndrome patients. Varicocele--a swollen vein inside the scrotum--can also inhibit sperm production. According to the Mayo Clinic, some men even have anti-sperm antibodies in their immune system that attack sperm as they are produced.
- Smoking and obesity have been linked to a low sperm count; so has the abuse of other substances, such as cocaine or marijuana. Even men who ride bicycles frequently have been known to suffer a reduced sperm count as a result.
- Though it is true that a man can father a child at any age, with increased age comes decreased sperm count. According to babyhopes.com, "Fertilization rates are usually over 60 percent for men under 39 but for those over that age, the rates fall to slightly over half."
- Exposure to harsh chemicals may reduce sperm count. Exposure to radiation or heavy metals (such as lead) can also reduce sperm count. Exposure to elements such as these would have to be prolonged over time in order to physically harm anyone.
- Some causes of low sperm count, such as varicocele, can be treated with surgery. Others can be aided with hormone replacement therapy or prescription drugs. In severe cases, couples who wish to have children may seek assistance with in vitro fertilization to combat low sperm count. For lifestyle causes, changes in lifestyle can reverse the effects.
