The testicles are the male sex glands that are located behind the penis and are contained in a sac called the scrotum. The main functions of the testicles are to produce sperm, the male reproductive cell, and the male hormone testosterone. Swollen testicles, either with or without pain, may be caused by several different conditions, many of which are not serious.
Hydrocele
Hydrocele is the accumulation of fluid in the scrotum, resulting in swollen testicles. This is a common condition of infants, affecting up to 10 percent of males born according to the Mayo Clinic. Hydrocele is not a serious condition and will usually resolve on its own without treatment. In adults, hydroceles sometime occur as a result of inguinal hernia.
Spermatocele
A spermatocele, also called an epididymal cyst, is an abnormal growth (cyst) that occurs in the epididymis. The epididymis is the small coiled tube located behind each testicle that is responsible for storing sperm while it matures. The exact cause of spermatocele is unknown but may be caused by a blockage in the tubes leading to the epididymis.
The cyst is filled with a milky white fluid that may or may not contain sperm. This cause of testicle swelling is usually painless; however, the patient may feel sensation of heaviness in the groin.
Epididymitis
Epididymitis is inflammation of the epididymis that is often caused by a bacterial infection or sexually transmitted infections such as gonorrhea or Chlamydia. Because epididymitis is related to sexual diseases, it is most common in men between the ages of 20 and 39, according to doctors at The Mayo Clinic.
The swelling caused by epididymitis is usually painful and can trigger inflammation of the entire testicle, a condition called epididymo-orchitis. Other symptoms include painful or frequent urination, painful sexual intercourse, chills, fever, swollen lymph nodes and an unusual discharge from the penis.
Varicocele
Varicocele is the enlargement of the internal veins that drain the testicles. This condition is very common, occurring in 15 percent of the male population as reported by the Center for Male Reproductive Health and Vasectomy Reversal. Varicocele occurs when the valves that control the flow of blood from the testicle back into the abdomen are not functioning properly. This results in a back-up of blood in the veins, causing them to swell. Varicocele can also cause lumps on the testicle and swelling of the scrotal sac and result in infertility.
Testicular Cancer
Swollen testicles are a common symptom of testicular cancer. In fact according to TC-cancer.com, more than 90 percent of patients go to the doctor because of a testicle lump or mass. This is the most serious cause of testicular swelling and is why any abnormality should be examined by a doctor.
