What kidney stones are
Stones form when minerals in the urine crystallise and clump together. A stone sitting quietly in the kidney may cause nothing at all. Pain usually starts when a stone moves into the ureter, the narrow tube between kidney and bladder, and obstructs the flow of urine.
Typical symptoms
- Severe pain in the flank or side, often coming in waves
- Pain that radiates towards the groin
- Blood in the urine
- Nausea and vomiting
- Needing to pass urine urgently or frequently
Seek urgent care if
Stone pain with a fever, shaking chills, or an inability to keep fluids down needs emergency assessment the same day, not a clinic appointment. An obstructed kidney with infection is a medical emergency — go to your nearest emergency department.
Treatment
Many small stones pass on their own with fluids, pain control and time, sometimes helped by medication that relaxes the ureter. Larger stones, stones that will not pass, or stones causing obstruction may need a procedure to break up or remove them. Which approach suits you depends on the size, position and composition of the stone.
Preventing the next one
Once you have had a stone, your risk of another is meaningful — which makes prevention worth taking seriously. Depending on what your stone was made of, that can involve fluid targets, specific dietary changes, and sometimes medication. Analysing a stone you have passed is genuinely useful, so keep it if you can.