Fiducia TogetherKidney cancer
Over half are found by accident on a scan done for something else. When it does have symptoms, blood in the urine is the main one.
Important: This page is general information, not medical advice, and it is not a diagnosis. If you are worried about your health or someone else's, speak to a GP, pharmacist, or call 111. In an emergency, call 999.
What it is
Cancer of the kidney, most commonly renal cell carcinoma. It is one of the cancers rising fastest in the UK, largely alongside smoking, obesity and high blood pressure.
More than half are now found incidentally, on a scan arranged for back pain or an unrelated problem. That is why so many are caught early and why survival has improved: an incidental finding is usually a small, curable tumour.
When symptoms do appear they are blood in the urine, a persistent ache in the side, or a lump. The classic textbook triad of all three together is rare and, when present, usually late.
Treatment for small tumours is often surgery alone, sometimes removing only part of the kidney. One healthy kidney is enough to live a normal life, which is worth saying early because people assume otherwise.
Signs you might notice
Blood in the urine: pink, red or brown, and often painless. Even once, in an adult, needs investigating.
Persistent pain or a dull ache in the side or lower back, below the ribs.
A lump in the side or lower back.
Unexplained weight loss, persistent tiredness, fever or night sweats.
High blood pressure that is new and hard to control, or a raised red blood cell count on a routine test.
Swelling of the veins in the scrotum, particularly on the left, in a man who has not had it before.
How it can affect day-to-day life
Living with an incidentally found cancer is a specific kind of shock: no symptoms, no warning, and a diagnosis from a scan for a bad back.
Some small tumours are watched rather than treated, which is appropriate and hard to accept.
After surgery, kidney function is monitored for life, and certain medicines including some painkillers need care. Ask which. See chronic kidney disease.
Immunotherapy and targeted treatments for advanced disease have changed the outlook substantially in the last decade, and have their own distinct side effects, some of which need reporting immediately rather than at the next appointment.
Supporting someone well
Blood in the urine, even once: GP, and ask for urgent referral. Do not accept a urinary infection as the explanation unless the blood clears afterwards.
Ask what the follow-up plan is, and keep the scans. Recurrence is monitored for years.
Ask about kidney function after surgery, and which medicines to avoid.
For immunotherapy, learn which side effects need reporting straight away. Some are serious and treatable if caught early.
Stop smoking, treat blood pressure, and address weight if that is on the table; all three affect the remaining kidney as well as the cancer.
Ask for the clinical nurse specialist's number.
Where to get help
A GP practice urgently for blood in the urine or a persistent flank lump or ache.
The urology clinical nurse specialist.
Kidney Cancer UK run a support line and publish patient guides.
Macmillan Cancer Support on 0808 808 00 00.
Last reviewed 2026-08-28 by Fiducia Together · Next review due 2027-08-28
Important: This page is general information, not medical advice, and it is not a diagnosis. If you are worried about your health or someone else's, speak to a GP, pharmacist, or call 111. In an emergency, call 999.