Infertility is medically defined as the inability to become pregnant after one full year of trying. Although both females and males can have problems that lead to difficulty conceiving, ninety percent of MALE infertility derives from a deficient sperm count. Because most sperm are destroyed before they even reach the egg, a count below 500 sperm per milligram can make conception very difficult. Let's look at some medical difficulties that can lead to infertility. A varicocele is an abnormally enlarged vein in the scrotum which occurs in 40 percent of infertile men. Varioceles can cause blood to pool in the scrotum, raising temperatures and killing sperm there. Testicular overheating, and consequential sperm death, can also be caused by high fevers and excessive hot tub or sauna use. In up to 70 percent of men who struggle with infertility, infection of the reproductive organs is a problem. This can stem from any number of issues, but is commonly a result of the sexually transmitted disease chlamydia. Another medical problem that can lead to male infertility is hormone release. Low levels of the male hormone testosterone, or particularly high levels of the female hormone estrogen, can both lead to conception difficulties. Sometimes, infertility can be related to a man's environment. For example, emotional and physical stress can impair the production of sperm, lowering levels until they become almost non-existent. Exposure to environmental toxins and chemicals can further lower a man's sperm count. Because sperm are so vulnerable to the damage of free radicals like these, doctors have found sperm counts to be falling dramatically in the past few decades of increased pollution and industry. Another reason for decreasing sperm count relates to consumption. A diet deficient in the vital Vitamins E and C, and in the nutrients zinc and folate, can lead to low sperm count and infertility. Consumption of illegal drugs can play a role, too. Abuse of drugs like cocaine and marijuana temporarily reduce the quantity and quality of sperm by up to 50 percent. Cigarette smoking also impairs sperm movement and lowers fertility in men. A final factor that can adversely affect male fertility is...not surprisingly...aging. As a man grows older, he will experience a decrease in sperm movement, as well as an overall decline in the genetic quality of the sperm he releases. Because there are so many reasons that a man may be infertile, it is important to talk to your doctor if you are part of a couple that is having trouble conceiving. A variety of treatment options may be able to help!