Kidney Stones
Hard crystal clumps that form in the kidney and can cause some of the worst pain in medicine on their way out. Most pass on their own. The real win is stopping the next one.
Typical signs: severe pain that comes in waves, in one side of the back, side, lower tummy or groin. Nausea, vomiting, blood in the urine and an urgent need to go are common. Some stones cause no symptoms.
How common: about 1 in 11 people get one in their lifetime, men about twice as often. About 1 in 4 have another within 5 years, and about half within 10.
Why it happens: concentrated urine (not drinking enough), a diet high in salt and meat, lots of soft drinks, a family history, extra weight and some medicines. About 3 in 4 are calcium stones.
Diagnosis: urine and blood tests, and a CT scan or ultrasound.
The kidney stone ladder
First control the pain and rule out infection. Then let small stones pass. Then change your urine chemistry so it doesn’t happen again.
- Step 1 · PrescriptionPain reliefAnti-inflammatories are the first choice, with stronger pain relief if needed.
- Works
- Anti-inflammatories work well and avoid opioid side effects
- Cost
- About $5–15, or given in hospital
- How long
- Until the stone passes
- Watch for
- Anti-inflammatories aren’t for everyone (kidney problems, ulcers).
Nothing about this pain is “just a twinge”.
- Step 2 · Self-careLet it passDrink clear fluids, take pain relief, and strain your urine to catch the stone for testing.
- Works
- About 8 to 9 in 10 stones pass on their own; it can take up to 6 weeks
- Cost
- Free (a tea strainer works)
- How long
- Days to 6 weeks
- Watch for
- Fever or uncontrolled pain means emergency, not waiting.
Catch it. Your urologist will want to meet it.
- Step 3 · PrescriptionTamsulosin (to help it pass)A tablet that relaxes the ureter.
- Works
- About 12 more in 100 pass their stone than with placebo, about 3 days sooner. Helps stones over 5 mm; no clear benefit for smaller ones
- Cost
- Prescription; low cost
- How long
- Until the stone passes
- Watch for
- Dizziness, especially on standing; slightly more side effects than placebo.
Opens the exit a little wider.
- Step 4 · ProcedureUrologist proceduresLaser through a thin scope (ureteroscopy), shockwave lithotripsy, or keyhole surgery for large stones.
- Works
- Used when a stone is large, won’t pass or pain isn’t controlled
- Cost
- Public hospital care is free; private fees vary
- How long
- Usually day surgery or a short stay
- Watch for
- Bleeding and infection.
Plan B, and a very good one.
- Step 5 · Self-carePrevention: water and saltDrink enough to make at least 2–2.5 litres of urine a day, which means more fluid than that, especially in hot weather. Less salt and meat, normal dairy calcium, and lemon juice may help.
- Works
- The main prevention tool, recommended for everyone who has had a stone
- Cost
- Free
- How long
- For life
- Watch for
- Pale urine is the target.
Hydrate like it’s your job. Your kidneys will notice.
- Step 6 · PrescriptionPrevention medicinesBased on stone testing: thiazide tablets for high urine calcium, or potassium citrate for low urine citrate.
- Works
- Large reductions in new calcium stones reported (about 80% in one long-term citrate study)
- Cost
- Under the $25 PBS co-payment for many
- How long
- Long term
- Watch for
- Thiazides can raise uric acid; blood tests are needed.
For repeat offenders, chemistry beats willpower.
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Cutting out dairy and calciumVery low calcium intake isn’t recommended and may backfire. Keep normal dairy.
- Cranberry juiceNot shown to prevent stones, and a sugary drink besides.
- Tamsulosin for small stonesUnder 5 mm, it doesn’t clearly help. Small stones usually pass anyway.
What you can do
- Strain your urine and keep the stone for testing.
- Keep a water bottle handy and drink more in hot weather or exercise.
- Go easy on salt, processed meat and soft drinks.
- Ask your GP about stone and urine testing if you’ve had more than one.
See your GP if
- You think you’ve had renal colic, even if it settled
- The stone hasn’t passed after a few weeks
- You’ve had more than one stone
- Blood in your urine
Get emergency help (call 000 (Australia) or your local emergency number. From a mobile, 112 works in most countries.) for kidney-stone pain with fever or shivers, if you have only one kidney, or if pain or vomiting can’t be controlled. A blocked, infected kidney is an emergency.
Common questions
Will I get another kidney stone?
About 1 in 4 people have another within 5 years and about half within 10. Drinking more, less salt and stone-specific treatment lower the risk.
Will my kidney stone pass on its own?
Most do: about 8 to 9 in 10 pass without a procedure, which can take up to 6 weeks. Larger stones are less likely to pass and may need a urologist.
How much water should I drink to prevent kidney stones?
Enough to make at least 2 to 2.5 litres of urine a day, which means drinking more than that, especially in heat. Pale urine is a good guide.
Should I stop eating dairy?
No. Very low calcium intake is not recommended for stone prevention. Normal amounts of dairy are fine; cutting salt and meat helps more.
Helpful resources
- Healthdirect: Kidney stonesSymptoms, treatment and prevention, with Australian services. Free, Australia.
- Cochrane: Tablets to help stones passPlain-language summary of the tamsulosin evidence. Free.
Evidence and more information
- Healthdirect: Kidney stones
- StatPearls: Renal calculi, nephrolithiasis
- Cochrane: Alpha-blockers for ureteral stones
maladywise.com/kidney-stones/