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what are kidney stones

Kidney stones are hard, crystal-like deposits that form in your kidneys when minerals and salts in your urine stick together and build up into “stones.”

Quick Scoop

What are kidney stones?

  • They are pebble-like pieces of material that can form in one or both kidneys when substances like calcium, oxalate, or uric acid become too concentrated in the urine.
  • They can be as small as a grain of sand or as large as a pea, and rarely can grow to golf-ball size.
  • Some stones stay in the kidney; others travel down the ureter (the tube from kidney to bladder), which is often when they cause severe pain.

Main types of kidney stones

  • Calcium stones (calcium oxalate and calcium phosphate): The most common type; linked to diet, low fluid intake, and certain metabolic issues.
  • Uric acid stones: Related to high levels of uric acid, often from a diet high in animal protein or certain metabolic conditions.
  • Struvite stones: Usually form after urinary tract infections and can grow quickly, sometimes becoming large “staghorn” stones.
  • Cystine stones: Caused by a rare inherited disorder (cystinuria) where too much cystine leaks into the urine.

Symptoms (and when they show up)

Small stones may cause no symptoms at all and pass without you noticing.

When symptoms do appear, they often include:

  • Sudden, severe pain in the side, back, or below the ribs
  • Pain that can move to the lower abdomen or groin
  • Pain or burning when you urinate
  • Blood in the urine (pink, red, or brown pee)
  • Cloudy or foul-smelling urine
  • Needing to pee more often or urgently
  • Nausea and vomiting
  • Fever or chills (this can mean infection and is an emergency)

If you have severe pain, fever, or cannot pass urine, you should seek urgent medical care.

Why kidney stones form (in simple terms)

Stones form when there is an imbalance: too many stone-forming minerals, not enough fluid, or not enough substances that naturally prevent crystals from sticking together.

Common contributing factors:

  • Not drinking enough water
  • Diet high in salt, animal protein, or oxalate-rich foods (like spinach, nuts, chocolate)
  • Certain medical conditions (e.g., gout, hyperparathyroidism, recurrent urinary infections)
  • Family or personal history of stones
  • Obesity and some digestive conditions or surgeries

Treatment at a glance

Treatment depends on the size, location, and type of stone, plus your symptoms.

  • Small stones
    • Drink plenty of fluids to help flush the stone.
* Pain relief (often NSAIDs, if safe for you).

* Medicines like alpha-blockers (e.g., tamsulosin) to relax the ureter so the stone passes more easily.
  • Larger or stuck stones
    • Shock wave lithotripsy: sound waves break the stone into smaller pieces.
* Ureteroscopy: a thin scope goes up through the bladder/ureter to remove or laser-fragment the stone.

* Percutaneous nephrolithotomy: a minimally invasive surgery through the back for very large or complex stones (like staghorn stones).

Kidney stones rarely cause permanent damage if they are recognized and treated properly.

Can you prevent kidney stones?

You usually can lower your risk, especially if you have had a stone before.

  • Drink enough fluid so your urine is pale yellow (water is best).
  • Limit excess salt and very high animal-protein intake.
  • For certain stone types, adjusting oxalate-rich foods or adding dietary calcium (under medical guidance) can help.
  • If you form recurrent stones, doctors may prescribe medications tailored to your stone type and urine chemistry.

Information gathered from public forums or data available on the internet and portrayed here.