A kidney stone is a hard deposit that forms when minerals in the urine become too concentrated and crystallise. Small stones may pass unnoticed, but larger ones can cause intense pain. Once you have had a stone, your chance of another is high — which is why prevention matters.
Types of kidney stones
| Type | Often linked to |
|---|---|
| Calcium oxalate (most common) | Low fluid intake, high oxalate/salt diet |
| Uric acid | High animal-protein diet, gout, acidic urine |
| Struvite | Certain urinary infections |
| Cystine (rare) | An inherited condition |
Symptoms of an attack
- Severe, cramping pain in the side or back that comes in waves
- Pain spreading to the lower abdomen and groin
- Blood in the urine (pink, red or brown)
- Nausea, vomiting, or a burning feeling when urinating
- Fever and chills (may signal infection — seek urgent care)
How stones form and travel through the urinary tract.
Seven ways to prevent stones
- Drink more water. Aim for enough fluid to pass about 2–2.5 litres of pale urine a day — the single most effective step.
- Cut back on salt. High sodium pushes more calcium into the urine.
- Don't over-restrict calcium. Normal dietary calcium actually helps bind oxalate in the gut. Get calcium from food rather than supplements unless advised.
- Limit high-oxalate foods if you form calcium-oxalate stones (spinach, nuts, beetroot).
- Moderate animal protein to lower uric-acid stone risk.
- Add citrus. Lemon and lime juice raise urinary citrate, a natural stone inhibitor.
- Maintain a healthy weight and stay active.
Catch the stone
If you pass a stone, try to collect it. Laboratory analysis of its composition lets your doctor tailor prevention precisely to your stone type.
How are stones treated?
Many small stones pass on their own with fluids and pain relief. Larger or stuck stones may need procedures such as shock-wave lithotripsy (ESWL), ureteroscopy, or keyhole surgery. Your urologist or nephrologist will advise based on the stone's size and location.
References & Further Reading
- National Kidney Foundation. "Kidney Stones." kidney.org
- NIDDK, National Institutes of Health. "Kidney Stones." niddk.nih.gov
- National Kidney Foundation. "Kidney Stone Diet Plan and Prevention." kidney.org
This article is for general education only and does not replace personalised medical advice. Seek urgent care for severe pain, fever, or inability to pass urine.