Low sperm count means that the fluid (semen) you ejaculate during an orgasm contains fewer sperm than normal.A low sperm count is also called oligospermia (ol-ih-go-SPUR-me-uh). Your sperm count is considered lower than normal if you have fewer than 15 million sperm per milliliter of semen. Having a low sperm count decreases the odds that one of your sperm will fertilize your partner's egg, resulting in pregnancy.

Symptoms

The main sign of low sperm count is the inability to conceive a child. There might be no other obvious signs or symptoms. In some men, an underlying problem such as an inherited chromosomal abnormality, a hormonal imbalance, dilated testicular veins or a condition that blocks the passage of sperm may cause signs and symptoms. Low sperm count symptoms might include: • Problems with sexual function — for example, low sex drive or difficulty maintaining an erection (erectile dysfunction) • Pain, swelling or a lump in the testicle area • Decreased facial or body hair or other signs of a chromosome or hormone abnormality

Causes

The production of sperm is a complex process and requires normal functioning of the testicles (testes) as well as the hypothalamus and pituitary glands — organs in your brain that produce hormones that trigger sperm production. Once sperm are produced in the testicles, delicate tubes transport them until they mix with semen and are ejaculated out of the penis. Problems with any of these systems can affect sperm production. Also, there can be problems of abnormal sperm shape (morphology), movement (motility) or function. However, often the cause of low sperm count isn't identified.