Several conditions may cause the scrotum to swell. The sections below outline some of these potential causes.

Hydroceles and hernias

Hydroceles and hernias are among the most common causes of scrotal swelling.

A hydrocele is a collection of fluid that builds up around a testicle. Hydroceles sometimes occur during early development.

In such cases, the testicles descend into the scrotum and leave behind an irregular opening that does not close. This opening causes fluid to accumulate in the scrotum and around the testicles. Around 10% of males have a hydrocele at birth.

Hydroceles can also occur later in life and may be the result of an injury or infection. However, many hydroceles occur for no apparent reason.

Hydroceles often do not cause symptoms. However, some males may notice a sense of heaviness or fullness in the scrotum.

Hernias, meanwhile, develop when a portion of the intestines passes through the same opening that a hydrocele can pass through. The primary symptom of a hernia is an unexplained swelling.

Around 1–5% of males have a hernia at birth, and it is particularly common among premature babies. Older males may develop a hernia when a weakness in the groin causes the bowels to drop down. Regular straining during bowel movements and lifting can increase this risk.

Hernias are also more common among males with obesity, as the extra weight puts pressure on the weak spot in the groin.

Cysts

A cyst is a small, enclosed collection of fluid. It may feel similar to a pimple deep beneath the skin or in the scrotum. Some cysts are around the size of a pea, while others can grow large enough to put pressure on the scrotum.

Sometimes, a cyst can develop in the epididymis. This is a tube that connects the testicles to a gland called the vas deferens. Doctors refer to these cysts as epididymal cysts, or spermatoceles.

They can sometimes develop following an injury or infection. However, in most cases, doctors are unable to determine a specific cause.

Varicoceles

A varicocele is a swollen collection of veins in the scrotum. If a varicocele develops during puberty, it may slow the growth of one of the testicles.

Most varicoceles do not cause any symptoms. However, some males report pain or swelling. In some cases, males with a varicocele can also experience reproductive difficulties.

Injury

Sustaining an injury to the groin can cause swelling that may feel tender or very painful to the touch.

Swelling that is very painful or lasts more than a day or two may signal a serious injury. Males who experience such swelling should see a doctor as soon as possible.

Tumors

Rarely, a swelling in the scrotum may indicate a tumor.

Tumors in the testicles are particularly rare among children under 15 years of age and account for only 2% of childhood cancers. Testicular cancer is more likely to occur among males aged 20–34 years. However, it is still one of the less common types of cancer.

Nonetheless, it is important to have a doctor investigate any swelling or other changes to the scrotum. According to the National Cancer Institute, most testicular cancers are curable, even when a doctor diagnoses them at an advanced stage.

Idiopathic swelling

Idiopathic swelling refers to swelling that a doctor has been unable to identify a reason for. This is more common among children, but it can affect males of any age.

This type of swelling may appear suddenly. It is painless and usually goes away on its own within around 3–6 days.

In order to diagnose the cause of scrotal swelling, a doctor will carry out a physical examination of the testicles and scrotum. They may also take a full medical history and ask about any other symptoms or recent injuries.

In some cases, an ultrasound or other imaging test may help rule out certain causes of scrotal swelling.

If a doctor suspects a tumor, they may recommend a biopsy or the removal of the tumor. A laboratory technician will then analyze the biopsy or tumor for signs of cancer.

In many cases, a doctor will prescribe pain relievers or anti-inflammatory medications to reduce scrotal swelling and discomfort.

However, other treatments for scrotal swelling will depend on the exact cause. The following sections list some potential treatment options by cause.

Hydroceles

Hydroceles do not always require treatment, especially when they develop in a newborn baby or young child. They will usually close up on their own.

In some cases, a doctor may recommend a procedure to suction fluid from the hydrocele. However, it may still come back, requiring further treatment.

A hydrocele that causes pain may require surgical treatment. Some surgical repairs are possible on an outpatient basis using only local anesthetics.

Hernias

A hernia will not go away on its own. As a result, most doctors recommend surgery to repair the hole, especially if the hernia is large or causes symptoms.

Cysts

Some cysts do not require any treatment. However, a doctor can drain a cyst that is particularly large or painful.

Varicoceles

Varicoceles usually only require treatment if they cause symptoms or affect fertility. There are several different surgical options a doctor can recommend to repair the veins.

It is important to discuss these options with a doctor before deciding on an approach.

Tumors

The treatment options for testicular tumors depend on the type of cancer and its stage. Some males need surgery only, while others require chemotherapy, radiation therapy, or other cancer therapies.

Most causes of scrotal swelling are relatively harmless. The main symptoms tend to be pain or a feeling of fullness in the scrotum.

If a person does not seek treatment, some causes of scrotal swelling may damage the testicles and cause infertility. Tumors may spread to other areas of the body, potentially becoming life threatening.

For this reason, it is important that males who notice any signs of scrotal swelling see their doctor for a diagnosis and appropriate treatment.

Undergoing surgery to repair swelling in the scrotum is generally safe, though all surgeries carry some risks. It is important to talk to a doctor or surgeon about the potential risks and benefits of a surgical treatment.

Males should see a doctor if they experience any swelling in the scrotum. Scrotal swelling is rarely an emergency, but untreated swelling could injure the testicles, scrotal blood vessels, or other important structures within the scrotum. In some cases, this may also affect fertility.

A doctor might refer someone with scrotal swelling to a urologist. Urologists specialize in treating conditions of the urinary tract and the male reproductive organs. These healthcare professionals will work with a person to diagnose the cause of scrotal swelling and explore appropriate treatment options.

Summary

Scrotal swelling can be alarming, but the cause is often benign. However, it is still best to see a doctor as soon as possible. This is because some causes of scrotal swelling can cause damage to the testicles and other important structures within the scrotum.

It is also important to rule out more serious causes of scrotal swelling, such as cancer.

In some cases, a doctor may refer someone with scrotal swelling to a urologist. They will work to diagnose the cause of the swelling and recommend appropriate treatment options.

Scrotal swelling can be alarming, but the cause is often benign. However, it is still best to see a doctor as soon as possible. This is because some causes of scrotal swelling can cause damage to the testicles and other important structures within the scrotum.

It is also important to rule out more serious causes of scrotal swelling, such as cancer.

In some cases, a doctor may refer someone with scrotal swelling to a urologist. They will work to diagnose the cause of the swelling and recommend appropriate treatment options.