--- title: "Kidney stones: Symptoms, Causes & Treatment | HealthAnswers" description: "Kidney stones cause sudden severe loin or groin pain — what they feel like, pain relief, when to go to A&E, and how the NHS treats them." url: https://healthanswers.co.uk/conditions/kidney-stones/ robots: noindex --- # Kidney stones: Symptoms, Causes & Treatment | HealthAnswers Health A–Z Kidney stones cause sudden severe loin or groin pain — what they feel like, pain relief, when to go to A&E, and how the NHS treats them. Written by HealthAnswers editorial team Medically reviewed by [HealthAnswers UK doctor review panel](https://healthanswers.co.uk/our-doctors/) Reviewed 3 July 2026 ## Quick answer What are kidney stones? Kidney stones are hard lumps that can form in the kidneys from waste products in the blood. Small stones may pass on their own with pain relief and plenty of fluids, but larger ones can cause severe pain and may need treatment. Staying well hydrated helps prevent them. ## Who is this page for? This page is for people in the UK who want a plain-English overview of Kidney stones, including when to seek help and what NHS care usually involves. It explains general information, not what is wrong with you personally. ## Who should skip this page? Skip this page if you need a diagnosis, a prescription, or emergency care. It cannot replace a GP, pharmacist, NHS 111 or 999. If you are in immediate danger, call 999; for urgent advice that is not life-threatening, call 111 in England, Scotland or Wales, or use your GP out-of-hours service in Northern Ireland. On this page 6 sections ## Key facts about kidney stones - Kidney stones are hard deposits that form in the kidneys. - Small stones may pass on their own; larger ones can need treatment. - They can cause severe pain in the side, back or lower tummy. - Drinking plenty of fluids helps prevent them. ## What are kidney stones? Kidney stones are hard lumps that can form inside the kidneys when waste products in the blood build up and crystallise. They vary in size, from tiny specks to larger stones. Small ones often pass out of the body unnoticed, but larger stones can become stuck and cause significant pain. ## Symptoms A kidney stone may cause: - severe pain in the side or back, often coming in waves - pain spreading to the lower tummy or groin - feeling sick or being sick - needing to pee more often, or pain when peeing - blood in the urine Some stones cause no symptoms at all and are found by chance. ## What causes them Stones form more easily if you do not drink enough fluid, so your urine becomes concentrated. Diet, being overweight, certain medical conditions and medicines, and a family history can all increase the risk. ## Treatment Treatment depends on the size and position of the stone. Small stones usually pass on their own — drinking plenty of fluids and taking pain relief helps. Larger stones, or those causing blockage or infection, may need a procedure to break them up or remove them, which a specialist will arrange. ## Preventing future stones The single most effective step is staying well hydrated so your urine is pale. If you have had a stone, a doctor may give specific dietary advice based on what the stone was made of, to reduce the chance of more forming. ## When it is urgent Severe pain, pain with a high temperature or shivering, blood in the urine, being unable to pass urine, or vomiting with the pain all need prompt medical attention, as a stone may be causing a blockage or infection. ## ! When to see a GP about kidney stones See a GP if you have ongoing or recurring pain that might be a kidney stone. Seek **urgent** help — call 111, or 999 if severe — for severe pain that comes in waves, pain with a high temperature, chills or shivering (a possible infection), being unable to pass urine, blood in your urine, or being sick with the pain. These can need prompt treatment. ## Common questions about kidney stones What does a kidney stone feel like? A stone often causes severe pain that comes in waves, usually in the side or back, and may spread to the lower tummy or groin. It can come with feeling sick, needing to pee more often, or blood in the urine. Some small stones cause no symptoms. What causes kidney stones? They form when waste products in the blood build up and crystallise in the kidneys. Not drinking enough fluid is a key factor, along with diet, being overweight, some medical conditions and a family history. How are kidney stones treated? Small stones often pass naturally with plenty of fluids and pain relief. Larger stones, or those causing problems, may need a procedure to break them up or remove them. A doctor will advise based on the size and position of the stone. How can I prevent kidney stones? The most important step is drinking plenty of fluids so your urine stays pale. Depending on the type of stone, a doctor may give dietary advice — for example on salt or certain foods — to reduce the chance of them returning. ## Sources - [NHS — Kidney stones](https://www.nhs.uk/conditions/kidney-stones/)