What Are the Testicles? What Do They Look Like?
Testicles also called testes are the male sex glands, which are located behind the penis in a pouch of skin called the scrotum. The testes produce and store sperm and are the body's main source of male hormones, such as testosterone. These hormones control the development of the reproductive organs and other male characteristics, such as body and facial hair, low voice, and wide shoulders.
Picture of the Male Urinary and Reproductive Structures
What Causes Swollen Testicles?
Testicle pain, discomfort, swelling, and soreness has many causes, some of which are surgical emergencies that require immediate medical attention in order to save the affected testicle.
Trauma to the testes often produces extreme pain. A direct blow to the scrotum, while very painful, usually causes only temporary pain. Most cases of testicular injuries (85%) are caused by blunt trauma (sports injuries, a direct kick or punch, car accidents, or straddle injuries). The injury may result in a bruise or swelling of the scrotal area and testes.
Occasionally, trauma to the testes may cause a more significant injury that may require emergency surgery.
Testicular torsion needs to be treated surgical immediately. This problem occurs when the testicle twists inside the scrotum, either spontaneously or less commonly, because of direct trauma. When the testicle twists, the blood vessels contained within the spermatic cord also twist leading to an interruption of blood flow to the affected testicle. The testes and the scrotal area require oxygen transported by the blood to remain functional and viable, and the twisting may result in the "death" of a testicle.
- Torsion can occur at any age, but it is most common in the first few months of life (newborns) and in boys between the ages of 12-18 years.
- Torsion often occurs in men who have an anomaly affecting the normal attachment of the testicle to the wall of the scrotum (referred to as the bell-clapper deformity). Many of these men have the same abnormality present in both testicles.
Torsion of a testicular appendage
The testicular appendage and the epididymal appendage are functionless tissue remaining from human embryonic development. As in testicular torsion, the twisting of these structures can lead to an interruption of blood flow, leading to varying amounts of testicular pain.
Torsion of a testicular appendage is a self-limiting condition and is a common cause of testicular pain in younger boys, in which most cases occur between the ages of 7 and 14 years.
- Epididymitis (inflammation of the epididymis) most often is due to an infection. It's the most common cause of testicular pain in men older than 18 years of age, though it can also occur in prepubertal boys and in elderly men.
- In sexually active men, the most common cause of epididymitis is a sexually transmitted disease (STD) such as gonorrhea or Chlamydia.
- Older and younger men also may get epididymitis, often because of an abnormality in the genitourinary system.
- In older men, enlargement of the prostate gland is a common cause.
What Are Less Common Causes of Swollen Testicles?
- Inguinal hernia: This condition occurs when part of the intestine protrudes through a muscular defect in the groin area and slides into the scrotum. This may cause scrotal swelling and testicular discomfort.
- Orchitis (inflammation of the testicle): This inflammatory condition of the testicle generally occurs because of an infectious process. It is sometimes found along with epididymitis (epididymo-orchitis), especially when epididymitis has gone untreated for several days. Most cases of orchitis are caused by a viral mumps infection, though other viruses and bacterial organisms can also cause it.
- Testicular tumor: A tumor rarely causes testicular pain. It is important to conduct regular self-examinations of the testicles to locate any lumps or masses, as early detection improves the prognosis for testicular cancer.
- Hydrocele: A fluid filled sac that forms around the testicle. Hydroceles, cause swelling, but very little pain.
- Edema to the Scrotum: Some men with congestive heart failure or kidney problems will retain fluid in their extremities (peripheral edema). The same edema can accumulate in the scrotum and cause swelling to the area.
- Kidney stone: The pain from kidney stones may sometimes radiate into the testicular area but usually does not cause swelling.
Testicular Cancer vs. Testicle Infection Symptoms and Signs
Testicular cancer is cancer of the testicle that may spread to other body parts. Testicle infections, for example, epididymis and orchitis, are caused by bacteria and/or viruses. Testicular cancer is one of most curable of all cancers, and most testicular infections also are curable.
Testicular cancer symptoms include a small painless lump, or pain in a
Symptoms of an infected testicle include:
- Abdominal pain
- Pain during sex or urination
- Blood in the urine or semen
What Are Other Symptoms and Signs of Swollen Testicles? Do They Cause Pain?
If you have testicular or scrotal pain, it is important for you to see a doctor to determine whether the pain is caused by testicular torsion, because this is a surgical emergency requiring prompt medical attention. Any male with testicular pain should not delay and see a doctor or other health care professional right away because trying to distinguish between the two conditions often can be difficult.
Pain from testicular torsion usually comes on suddenly. Pain from an infection of the testicle usually begins gradually. Early on, the pain due to the infection frequently is localized to the area of the infection itself.
With testicular pain from any source, you or your male child may have any of these symptoms:
Reviewed on 7/13/2018
American Urological Association. "Medical Student Curriculum: Acute Scrotum." Updated: Jul 2016.
Ching, CB, MD, et al. "Epididymitis." Medscape. Updated: Jan 22, 2018.
Ogunyemi, OI, MD, et al. "Testicular Torsion." Medscape. Updated: Jun 23, 2017.