A varicocele  is a bundle of enlarged veins in a man's scrotum, which is the sac that holds the two testicles. The veins are usually visible as lumps on the scrotum and feel like a bag of worms when massaged gently. The veins become enlarged because some of the tiny valves inside the veins don't close properly. The valves normally prevent blood from draining backwards. When the valves fail, blood pools in the veins, causing them to swell. Many men don't realize they have a varicocele because the veins typically don't hurt and don't change the feeling of orgasm or ejaculation.

Sperm are made in the testicles, which hang in the scrotum away from the body. This design is required because testicles need to be slightly cooler than normal body temperature to make sperm. Anything that warms the testicles will hurt sperm production. This is what a varicocele does. The extra blood pooling in the enlarged veins warms the nearby testicle unnaturally and cuts sperm production.

About 20% of the male population have some kind of varicocele. Varicoceles are probably the result of very subtle genetic effects which, a present, remain unknown. Sometimes varicoceles begin to form in the teen years, which is cause for concern. Untreated adolescent varicoceles can result in under-sized testicles, lower semen volumes, lower sperm counts, and more misshapen sperm.

But varicoceles can happen at any age…and in general, the older you are the more likely you are to have a varicocele. Unfortunately, many doctors still don't recognize the role that varicoceles play in male infertility and may minimize the importance of having a varicocele corrected surgically.

Since they seldom cause any pain or discomfort, most varicoceles are discovered during routine physical exams, or exams associated with an infertility work-up. Physicians typically diagnose varicoceles by asking the man to stand up, take a deep breath, and bear down while the physician feels the scrotum above the testicle. If a varicocele is suspected, a physician may order a scrotal ultrasound test, but this is fairly uncommon because the classic "bag of worms" feel of a varicocele is so distinctive.

Varicocele repair surgery is relatively simple. The goal is to locate the distended veins and tie them off or block them to prevent blood from pooling. There are three main surgical techniques used to correct a varicocele and one non-surgical technique. Which method is best depends on the particulars of a man's anatomy, the nature and location of the varicocele, whether previous surgery has been performed, and other factors such as surgeon preference and/or amount of experience.

Most commonly, surgery is performed through a single incision in the lower abdomen on the affected by the varicocele.

No special preoperative tests are needed before a varicocele repair other than the standard lab tests required by some hospitals, ambulatory surgery facilities or anesthesiologists

Varicocele repair may be performed with local, regional, or general anesthesia, depending on the preference of surgeon and patient. General anesthesia is commonly used because it affords maximum patient comfort during the surgery.

Varicocele surgery is usually done on an outpatient basis, and recovery us usually rapid. Pain is usually mild. Swelling around incisions usually goes away after several days, and discoloration of the scrotum will resolve in a week or so. You shouldn't lift anything heavy or exercise strenuously for two weeks, although office work can typically be done one to two days after surgery.

It is generally best to wait three weeks after the surgery before resuming any type of sexual activity.

It takes about three months for sperm cells to be created and matured. A follow-up semen analysis is thus usually obtained three to four months after the surgery. The physician will evaluate the number and health of the sperm and compare this with a sample taken before the procedure. Improvement is often seen within six months, but may not be observed until one year after the surgery. Semen quality is improved in about 60 percent of infertile men undergoing correction of a varicocele.