In short: Most testicular lumps and swellings are not cancer, but any new lump, swelling or change in the shape or feel of a testicle should be checked by a GP promptly. Sudden, severe testicular pain is a medical emergency (it may be testicular torsion): call 999 or go straight to A&E. Checking your testicles regularly helps you notice changes early.

This guide, written by a Ready Health prescribing pharmacist in Standish, Wigan, explains how to check your testicles, the common causes of lumps and pain, and what NICE guidance says about referral.

When is testicular pain an emergency?

Call 999 or go to A&E immediately if you have:

sudden, severe pain in a testicle or the scrotum
pain with feeling sick or vomiting, or pain spreading to the lower tummy
a testicle that has become swollen, red or sits higher than usual after sudden pain
pain or swelling after a significant injury

These can be signs of testicular torsion, where the testicle twists and loses its blood supply. It needs surgery within hours to save the testicle.

How do you check your testicles?

A quick check about once a month helps you learn what is normal for you:

Check during or after a warm bath or shower, when the scrotum is relaxed.
Hold the scrotum in your palm and gently roll each testicle between your thumb and fingers.
Feel for lumps, swellings or changes in size, shape, firmness or texture.
At the top and back of each testicle you will feel a soft tube (the epididymis). This is normal.
It is common for one testicle to be slightly larger or to hang lower than the other.

What can cause a testicular lump or swelling?

Cause	Typical features
Epididymal cyst	Smooth, painless lump, usually above or behind the testicle
Hydrocele	Fluid around the testicle causing painless swelling
Varicocele	Enlarged veins, often described as feeling like a "bag of worms", usually on the left
Epididymo-orchitis	Painful, swollen, warm testicle that develops over hours to days, sometimes caused by a sexually transmitted infection such as chlamydia or gonorrhoea
Inguinal hernia	Swelling in the groin that may extend into the scrotum
Testicular cancer	Often a painless lump or swelling within the testicle, or a change in its shape or firmness; sometimes a dull ache or heaviness

How common is testicular cancer?

Testicular cancer is uncommon overall, but it mainly affects younger men, typically those aged roughly 15 to 49. It is one of the most treatable cancers, particularly when found early, which is why checking yourself and reporting changes promptly matters.

What does NICE say about referral?

The NICE guideline on suspected cancer (NG12) advises GPs to:

consider a suspected cancer pathway referral (usually seen within two weeks) for a man with a painless enlargement of the testicle, or a change in its shape or texture
consider a direct-access ultrasound scan for unexplained or persistent testicular symptoms

An ultrasound scan of the scrotum is quick, painless and is usually the key test to find out what a lump is.

When should you see a GP?

Book a GP appointment, and do not wait to see if it goes away, if you notice:

a lump or swelling in either testicle, even if painless
a change in shape, size or firmness
a heavy feeling in the scrotum or a dull ache in the groin or lower tummy
pain or swelling that builds up over hours or days, especially with discharge or pain when passing urine

Frequently asked questions

Is a painless lump less worrying than a painful one?

Not necessarily. Testicular cancer is often painless, so any new lump should be checked.

Is it normal for one testicle to be bigger?

Yes, a small difference is common. A new or changing difference should be checked.

Can an STI cause testicular pain?

Yes. Infections such as chlamydia and gonorrhoea can cause epididymo-orchitis. Testing and treatment of you and recent partners is important.

What happens at the appointment?

The clinician will ask about your symptoms and examine you, usually lying down and standing. They may test your urine and arrange an ultrasound scan or blood tests.

Key takeaways

Sudden severe testicular pain is an emergency: call 999 or go to A&E.
Most lumps are not cancer, but every new lump or change needs checking.
Check your testicles about once a month so you know what is normal for you.
Ultrasound is the usual first test for a scrotal lump.

Sources and further reading

Last reviewed: October 2026 by Shamir Patel, Independent Prescribing Pharmacist, Ready Health. This article is general information and does not replace advice from your own clinician.

If you have noticed a change, please see your NHS GP promptly. For a private appointment, see our men's health clinic in Standish, Wigan, and read more about men's health MOT checks.