What Are Kidney Stones?
Kidney stones (renal calculi) form when minerals and salts crystallise in the kidneys. They may stay in the kidney or travel down the ureter to the bladder — it's during this journey that they cause excruciating pain (renal colic).
Symptoms
- Sudden, severe pain in the back or side (loin) that moves to the groin — 'colic'
- Haematuria (blood in urine)
- Nausea and vomiting
- Frequent urge to urinate
- Burning sensation when urinating
- Fever and chills if infection (UTI/pyelonephritis) develops
Seek Urgent Care If:You have a fever with loin pain — this suggests infection behind a blocked kidney (obstructed, infected kidney) which requires emergency drainage.
Types of Kidney Stones
| Type | Proportion | Associated Cause |
|---|---|---|
| Calcium oxalate | 80% | Dehydration, high-oxalate diet |
| Uric acid | 10% | Gout, high-purine diet, low urine pH |
| Struvite | 5% | Recurrent UTIs (urease-producing bacteria) |
| Cystine | Rare | Inherited cystinuria |
Diagnostic Tests
| Test | Purpose |
|---|---|
| Urine dipstick + microscopy | Haematuria; infection |
| Uric acid | High in gout-related stones |
| Calcium, PTH | Hyperparathyroidism as a cause |
| Kidney function (eGFR, creatinine) | Assess renal function |
| CT KUB (non-contrast) | Gold standard imaging — detects all stone types |
| 24-hour urine collection | After first stone: checks oxalate, citrate, calcium excretion |
FAQs
How can I prevent kidney stones?
Drink 2.5–3L of water daily. Reduce sodium and animal protein. Increase citrate foods (lemon juice). Avoid excessive oxalate foods if calcium oxalate stones.
Do all kidney stones need surgery?
Stones under 5mm often pass spontaneously with fluids and pain relief. Larger stones or those with obstruction may need ureteroscopy or shockwave lithotripsy.
Can kidney stones recur?
Yes — 50% recurrence within 10 years without preventive measures. Stone analysis and 24-hour urine testing guide prevention.
Medical Disclaimer: Severe loin pain with fever requires emergency hospital assessment — an obstructed infected kidney is a urological emergency.