The testicles, also called the testes, are an important part of the male reproductive system. Swollen testicles can affect anyone with testicles or testicular implants.

When swelling occurs, it may be due to a problem involving the testicles themselves or structures leading to or from them. These include the epididymis (a coiled tube situated at the back of each testicle) or the vas deferens (the tube that connects the epididymis to your urinary tract).

This article looks at the symptoms and causes of swollen testicles, including how the condition is diagnosed and treated. It also describes when swollen testicles are a sign of a medical emergency needing immediate care.

Symptoms of Swollen Testicles

The testicles are a pair of oval-shaped glands responsible for making sperm and the sex hormone testosterone. They are situated within a sac of skin beneath the base of the penis called the scrotum. Together, the testicles and scrotum are commonly referred to as “balls.”

The symptoms of swollen testicles can vary based on the underlying cause. While most cases are unilateral (involving only one testicle), some cases are bilateral (affecting both testicles).

Not every case is the same, and the range of symptoms a person experiences may suggest the underlying cause. These include symptoms like:

A swollen, red, or warm scrotum Testicle pain and tenderness, ranging from a dull ache to sudden, severe pain Pain or discomfort in the lower abdomen or pelvis Pain with movement or when lifting heavy objects A feeling of heaviness in the scrotum Abnormal testicle position, including a high-riding testicle Urinary problems, such as painful urination, frequent urination, or the need to pee urgently Discharge from the penis Blood in the urine Blood in the semen A discernible nodule on a testicle

Depending on the underlying cause, there may be accompanying symptoms like fever, nausea or vomiting, swollen lymph nodes, or unintended weight loss.

Causes of Swollen Testicles

It can be distressing to experience the sudden swelling of a testicle, particularly when there is pain. In some cases, this may be a sign of a serious medical situation. However, more often than not, it is related to a treatable medical condition.

There are severe common causes of testicular swelling a healthcare provider may explore during an evaluation.

Testicle Injury

Testicle injuries can easily occur if you are kicked, crushed, or struck in the groin. In some cases, an injury may seem mild and only cause symptoms hours later. At other times, a person may not even realize what caused an injury. An example of this is testicular swelling that occurs after a bike ride.

With certain blunt-force injuries, a person may also experience scrotal hematocele (a collection of blood in the scrotum).

Epididymitis

Epididymitis is a painful swelling of the epididymis. It may be caused by a bacterial or viral infection, such as a sexually transmitted infection (STI), urinary tract infection (UTI), or mumps (a contagious viral disease). It may also occur due to repetitive friction from a bicycle seat or a saddle.

Epididymitis often occurs alongside the swelling of the testicle itself, called orchitis. When both the testicle and epididymis are affected, it is known as epididymo-orchitis.

In addition to the pain and swelling, bacterial infections of the epididymis can lead to the formation of a pus-filled abscess. Gonorrhea and chlamydia are the most common bacterial causes of epididymitis.

Varicocele

A varicocele is a condition in which veins inside the scrotum, called the pampiniform plexus, become abnormally enlarged. It is thought to be the result of defective valves that cause blood to backflow and accumulate in the same way as varicose veins.

You may not realize you have a varicocele until you happen to feel an abnormally thickened vein inside your scrotum. You may also feel a dull ache or heaviness in the testicle, particularly after physical exertion.

Hydrocele

A hydrocele is the swelling of the scrotum due to the accumulation of fluids in the membrane surrounding the testicle. It can result from an injury, an infection, or an underlying condition that causes bodily fluids (such as abdominal fluids) to seep into the scrotum.

The condition generally is unilateral but can sometimes be bilateral.

Hydrocele usually affects infants but can occur in people of any age. The condition tends to be painless but can cause discomfort and embarrassment due to the often extreme swelling of the scrotum.

Inguinal Hernia

An inguinal hernia is when a part of your intestine pushes through a weak spot in your groin. It can create a visible bulge on the groin and extend into the scrotum, causing unilateral testicular swelling.

An inguinal hernia isn’t necessarily dangerous but can be painful, especially when you cough, bend over, or lift a heavy object. While some inguinal hernias cause no pain, the likelihood of pain increases the longer you leave it untreated.

Testicular Torsion

Testicular torsion is a serious medical condition in which the testicle and spermatic cord (which delivers blood to the testicle) are twisted. This cuts off the blood supply, triggering sudden and severe pain, swelling of the scrotum and/or lower abdomen, and a high-rising testicle. Nausea and vomiting are also common.

Testicular Cancer

Testicular cancer is a less common cause of swollen testicles that affects around 9,000 people in the United States yearly.

Testicular cancer causes the formation of a tumor that arises from changes in either testicular tissues or germ cells (cells that form sperm in males). These tumors are usually painless and unilateral and can range in size from a pea to larger than a marble. Testicular swelling is a central feature.

In addition to swelling, symptoms of testicular cancer can include fatigue, unintended weight loss, and swollen lymph nodes in the groin.

How to Treat Swollen Testicles

The treatment of swollen testicles varies based on the underlying cause. Some causes may not require any treatment, such as uncomplicated cases of varicocele or hydrocele, which often resolve on their own. Others, like inguinal hernia, may benefit from a watch-and-wait approach, while others still require aggressive medical intervention.

Testicular injuries and infections can impair fertility by damaging the epididymis, causing scar tissues that block the passage of sperm from the testicles. They can also damage certain ducts in the reproductive tract that contribute to spermatogenesis (the development of sperm cells).

While the removal of a testicle is a standard treatment of testicular cancer, a testicle can be lost for other reasons as well. With testicular torsion, for example, the obstruction of blood flow can deprive a testicle of oxygen, leading to rapid tissue death (atrophy). If the damage is severe enough, the testicle would need to be removed.

The delayed treatment of any cause of swollen testicles may result in testicular injury, sometimes irreversible. Since it can be difficult to tell the cause of the swelling by appearance alone, it is important to see a healthcare provider, particularly if the swelling is sudden, severe, or persistent.

Are There Tests to Diagnose the Cause of Swollen Testicles?

If you have swollen testicles, your healthcare provider will review your symptoms and medical history to identify possible causes. This would include asking you about recent injuries, your sexual history, or your family history of testicular cancer.

There would also be a physical exam to establish where exactly the swelling is located (such as in the epididymis, pampiniform plexus, or testicle itself), whether the swelling is unilateral or bilateral, and whether there are any nodules.

If there is a nodule, the healthcare provider will want to determine if it has characteristics of cancer.

Based on the initial findings, a healthcare provider will order different tests and procedures, including:

Complete blood count (CBC): This is a panel of blood tests that can detect signs of infection or inflammation. Urinalysis: This is an evaluation of your urine to help identify UTIs, the presence of blood, and other abnormalities. Scrotal ultrasound: This is a noninvasive test that uses sound waves to image structures and abnormalities within the scrotum. Transillumination: This involves the use of a bright light to illuminate structures within the scrotum. It can differentiate a benign cyst from a possibly cancerous tumor. STI screen: Typically with epididymitis, the healthcare provider will want to screen for gonorrhea and chlamydia. Tumor marker blood tests: If cancer is suspected, there are blood tests that can detect substances called tumor markers that are elevated when cancer is present.

When to See a Healthcare Provider

There are situations in which a swollen testicle is a sign of a medical emergency. Chief among these is testicular torsion. Unless treated in a timely manner, testicular torsion can lead to the loss of a testicle.

Seek immediate emergency care if you experience the signs and symptoms of testicular torsion, including:

Sudden and severe pain in the scrotumSwelling of the scrotumA testicle that is positioned higher than normal or at an unusual angleLower abdominal painNausea or vomitingFrequent urinationFever

Testicular torsion is most common in people under age 25, particularly those between the ages of 12 and 16. With that said, testicular torsion can occur at almost any age.

Summary

Swollen testicles can have many different causes, both serious and nonserious. These include testicle injuries and conditions like epididymitis, varicocele, hydrocele, inguinal hernia, and testicular torsion. Although testicular cancer is a less likely cause, swollen testicles are one of the defining symptoms.

Because it is difficult to identify the cause of swollen testicles by appearance alone, it is important to see a healthcare provider to ensure the proper diagnosis and treatment. If the swelling is sudden and accompanied by severe pain, go to your nearest emergency room.

A Word From Verywell

You may assume that a swollen testicle is not as serious if there is no pain. It is important to understand that conditions like varicocele, hydrocele, and inguinal hernias can all occur without pain and may get worse if left undiagnosed or untreated.

Swollen testicles caused by testicular cancer may cause no pain, particularly in the early stages. If diagnosed early before the cancer spreads (metastasizes), the five-year survival rate is a very optimistic 95%, However, if the diagnosis is delayed and metastasis occurs, the survival rate drops to 73%.

Swollen testicles, even when mild, should never be considered normal. See a healthcare provider or ask for a referral to a urologist who specializes in disorders of the urinary tract and male reproductive system.

Being under age 20Having an undescended testicleHaving one testicle that is larger than the otherHaving a condition present at birth called a bell-clapper deformity in which the spermatic cord attached to the testicle is able to rotate more freely

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