A varicocele is an enlarged vein, similar to a varicose vein that can occur in a leg, but instead it occurs within the scrotum, the loose bag of skin that holds a man's testicles. About one in six men have a varicocele. For males who are infertile, the figure is higher – about 40%. Varicoceles are the most common cause of low sperm production and decreased sperm quality, although not all varicoceles affect sperm production.
Varicoceles develop over time, are easy to diagnose and, if they cause symptoms, can be repaired surgically. They do not exhibit symptoms. Sometimes they cause pain that can get worse due to physical exertion, but generally this is relieved by lying down. Varicoceles may grow larger and become more noticeable over time.
It's not certain what causes varicoceles, but many experts believe abnormal valves within the veins prevent normal blood flow. The resulting backup causes the veins to widen (dilate). Varicoceles usually occur in the region of the left testicle, most likely because of the position of the left testicular vein. However, a varicocele in one testicle can affect sperm production in both testicles.
Because of the lack of symptoms, a varicocele often is discovered during an evaluation of fertility or during a routine physical exam. Men between the ages of 15 and 25 are at greater risk for varicoceles. A man experiencing pain or swelling in the scrotum should contact a doctor. A number of conditions can cause testicular pain, and some of the conditions require immediate treatment. Your doctor can determine which condition is causing your pain.
For more information go to Male Infertility.