Testicle lumps and swellings

A lump or swelling may be in a testicle or in the structures around it. These structures sit inside the scrotum, the loose skin sac below the penis.

Many scrotal lumps are caused by harmless fluid collections, cysts, or enlarged veins. Infection, a hernia, injury, and other conditions can also cause swelling. Less commonly, a solid lump in a testicle may be testicular cancer.

You cannot reliably identify the cause by touch alone. Arrange a medical appointment for any new lump, swelling, or change in a testicle, even if it is painless. Sudden severe pain is different and needs emergency assessment.

The change may affect one or both sides. You might notice:

• A small, smooth lump above or behind a testicle
• One side of the scrotum becoming larger
• A feeling of heaviness, fullness, or dragging
• A soft swelling that changes size
• Enlarged veins that feel like a soft bundle of cords
• Tenderness, warmth, or redness
• A firm area or change in the shape of a testicle

It is normal for one testicle to hang lower than the other. The epididymis, a soft coiled tube that stores sperm, can also be felt behind each testicle. If you are unsure whether something is normal for you, have it checked rather than repeatedly pressing it.

Epididymal cyst or spermatocele: This is a fluid-filled sac near the epididymis, usually above or behind the testicle. It is often smooth, painless, and separate from the testicle.

Hydrocele: Fluid collects around a testicle, making one side of the scrotum look or feel enlarged. It is often painless, although a large hydrocele may feel heavy or uncomfortable.

Varicocele: Veins in the scrotum become enlarged. They may feel like a soft bundle of cords and can cause an ache or dragging feeling, often after standing.

Epididymitis or orchitis: The epididymis or testicle becomes inflamed, often because of an infection. Pain and swelling usually develop over hours or days. There may also be fever, pain when urinating, or discharge from the penis.

Inguinal hernia: Part of the bowel or fatty tissue pushes through a weak area in the groin. This can cause a bulge that extends into the scrotum and may become more obvious when coughing, lifting, or standing.

Injury: A knock, sports injury, or other trauma can cause bruising and swelling. A collection of blood may sometimes form inside the scrotum.

Less common causes: These include inflammation without infection, skin cysts, and benign growths.

A firm lump within a testicle can be a sign of testicular cancer. It is often painless, but pain does not rule it in or out. Most scrotal lumps are not cancer, but any new solid-feeling change needs prompt medical assessment.

Go to an emergency department now if you have sudden, severe pain in one testicle, especially with swelling, nausea, vomiting, or lower abdominal pain. This may be testicular torsion, in which the cord supplying blood to the testicle twists. Treatment is time-sensitive.

Emergency care is also appropriate if:

• Severe pain follows an injury
• A groin or scrotal bulge becomes very painful, firm, or cannot be pushed back
• Pain is accompanied by vomiting or rapidly increasing swelling

Seek same-day medical care for increasing pain or swelling with fever, redness, warmth, pain when urinating, or penile discharge. These features may suggest infection and should not be managed with self-care alone.

Book a routine appointment soon for any painless lump, change in testicle shape or firmness, persistent swelling, or feeling of heaviness. Do not wait for it to become painful.

A clinician will ask when you noticed the change, whether it is painful, and whether it changes with standing, coughing, or activity. They may ask about injury, urinary symptoms, sexual health, and previous scrotal problems.

During an examination, they will gently feel both testicles and the surrounding structures. You may be examined while standing and lying down. A light may sometimes be shone through the swelling to see whether it contains fluid.

An ultrasound is commonly used when the cause is uncertain. It uses sound waves to show whether a lump is inside or outside the testicle, whether it contains fluid, and how blood is flowing.

Depending on your symptoms, you may also need urine tests or tests for sexually transmitted infections. Blood tests, including tests called tumour markers, may be used if the examination or ultrasound shows a suspicious testicular mass.

Treatment depends on the cause and how much it affects you. A small, painless cyst, hydrocele, or varicocele may only need monitoring. Larger or uncomfortable swellings can sometimes be treated with a procedure or surgery.

Bacterial infections are treated with antibiotics like amoxicillin or doxycycline chosen for the likely cause. Sexual partners may also need testing or treatment when a sexually transmitted infection is found. Testicular torsion requires urgent surgery.

While waiting for a routine appointment, supportive underwear may reduce heaviness or mild discomfort. A wrapped cold pack can help after a minor injury; do not place ice directly on the skin. Paracetamol or ibuprofen may help if you can take it safely and follow the package directions.

Do not squeeze, pierce, drain, or try to remove a lump yourself. Avoid relying on self-care if pain is severe, worsening, or accompanied by fever or vomiting.

Some painless cysts and fluid collections remain stable for years. Others slowly enlarge and may eventually need treatment if they cause discomfort or interfere with daily life.

Swelling from infection or injury should improve as the cause is treated, although tenderness may take longer to settle. Arrange follow-up if symptoms do not improve as expected, return after treatment, or a lump remains.

If tests suggest testicular cancer, you will be referred promptly to a specialist. Early assessment is important, and treatment is often effective. An examination or ultrasound does not automatically mean that cancer is suspected.

Can a painless lump be serious?

Yes, although many painless lumps are benign. Because testicular cancer may not cause pain, any new lump within a testicle should be examined promptly.

Can a lump affect fertility?

Some causes, including large varicoceles, severe infections, or problems affecting both testicles, can affect fertility. Many cysts and hydroceles do not. Ask about fertility testing if you have concerns or are having difficulty conceiving.

Should I keep checking the lump?

Notice whether it changes, but avoid frequent squeezing. Repeated handling can cause soreness and cannot determine the diagnosis. Arrange an examination instead.

Could it be related to sex?

Some cases of epididymitis are caused by sexually transmitted infections, but many testicle lumps are unrelated to sexual activity. Testing may be offered when symptoms or your history suggest an infection.