Overview
Kidney stones are hard deposits of minerals and salts that form inside the kidneys. Small stones may pass out in the urine on their own. Larger stones can lodge in the ureter — the tube from the kidney to the bladder — and block urine flow, which causes intense pain.
Stones are common in hot climates, where the body loses fluid through sweat and urine becomes concentrated.
Symptoms
- Severe, sharp pain in the side and back, below the ribs
- Pain that spreads to the lower abdomen and groin
- Pain that comes in waves and changes in intensity
- Pain or burning while passing urine
- Pink, red or brown urine
- Cloudy or foul-smelling urine
- Frequent urge to pass urine
- Nausea and vomiting
When to see a doctor
- Pain so severe you cannot sit still or find a comfortable position
- Pain with fever and chills
- Pain with nausea and vomiting
- Blood in your urine
- Difficulty passing urine
Causes
- Most stones are made of calcium oxalate
- Uric acid stones are linked to a high-protein diet and gout
- Struvite stones can form after urinary infections
- Cystine stones run in families
- Concentrated urine from low water intake lets crystals stick together
Risk factors
- Not drinking enough water
- A diet high in salt, sugar or animal protein
- Obesity
- A personal or family history of stones
- Some digestive diseases and surgeries
- Conditions such as gout and hyperparathyroidism
- Some medicines and supplements
Diagnosis
- Urine tests for blood, infection and crystals
- Blood tests for kidney function, calcium and uric acid
- Ultrasound of the kidneys and bladder
- Non-contrast CT scan (CT KUB), the most accurate test for stones
- Analysis of a passed or removed stone
Treatment
- Small stones: plenty of fluids, pain relief and medicines that relax the ureter to help the stone pass.
- Ureteroscopy (URS) with laser: a thin telescope passed through the urinary passage breaks the stone. No incision.
- RIRS: a flexible telescope reaches stones inside the kidney, which are broken with laser.
- PCNL / Mini-PCNL: for large stones, through a keyhole opening of a few millimetres in the back.
- A temporary DJ stent may be placed to keep urine draining while the ureter heals.
Prevention
- Drink enough water to keep urine pale — often 2.5 to 3 litres a day; ask your doctor what is right for you
- Cut down on salt and packaged foods
- Moderate meat, fish and egg intake
- Do not cut calcium from your diet unless your doctor advises it
- Ask for a stone analysis — prevention advice depends on stone type
FAQs
Can kidney stones be removed without a cut?
Yes. URS and RIRS reach the stone through the natural urinary passage, so there is no incision. Your urologist will advise which method suits the size and position of your stone.
How long will I stay in hospital?
Many patients go home within a day after URS or RIRS. PCNL usually needs a stay of two to three days. Your doctor will give you an estimate after the scan.
Will my stones come back?
Stones do recur in many people, often within some years. Drinking enough water, diet changes based on stone analysis and regular check-ups lower the risk.
Medical review: pending — Dr. Mukesh J. Shah · Content prepared October 2026. This guide is general information and does not replace a consultation.