What Do Kidney Stones Look Like?

Kidney stones are hard, crystal-like formations that can develop inside your kidneys when certain minerals and salts build up in your urine. They can vary in size, shape, and color. Some are tiny and pass unnoticed, while others may block your urinary tract and cause severe pain.

In this article, you’ll learn what kidney stones look like, what causes them, common symptoms, available treatments, and how to lower your risk.

What are kidney stones?

Kidney stones form when your urine contains more crystal-forming substances (like calcium or uric acid) than your body can flush out. When this happens, minerals clump together and solidify into stones.

They may be smooth or jagged, round or irregular. Most are yellow or brown, but color can vary depending on what they are made of.

What types of kidney stones are there?

There are four main kinds of kidney stones:

• Calcium stones: The most common type, made of calcium oxalate or calcium phosphate.

• Uric acid stones: Often smooth and pebble-like, linked to high uric acid levels.

• Struvite stones: Larger stones that often develop after urinary tract infections.

• Cystine stones: Caused by a rare inherited condition where cystine, an amino acid, leaks into urine. These stones are compact and amber-colored.

Learn more about how to check kidney function at home in our guide on kidney function test at home.

What symptoms should you look out for?

Common signs of kidney stones include:

• Sharp pain in your back, side, lower belly, or groin

• Blood in your urine (pink, red, or brown)

• Pain or burning when urinating

• Cloudy or bad-smelling urine

• Nausea, vomiting, fever, or chills

• Frequent urge to urinate, or difficulty urinating
  
  

If you’re worried about overlapping urinary symptoms, our UTI tests guide explains key differences and prevention.

What causes kidney stones?

Your kidneys normally filter and flush out waste. But if there’s too much waste and not enough liquid, crystals can form and harden into stones.

Dehydration, high salt intake, and certain health conditions make stones more likely to develop.

Can kidney stones pass on their own?

Yes. Smaller stones often pass naturally, though it can be painful. Drinking lots of water helps. Doctors may also prescribe:

• Pain relief medicine

• Anti-nausea drugs

• Tamsulosin, which relaxes the ureter to help stones pass more easily

The larger the stone, the less likely it is to pass without treatment. Stones over 6 millimeters usually require medical help.

What treatments are available?

If a stone is too large or causing a blockage, your doctor may recommend:

• Shock wave lithotripsy: Breaks stones into smaller pieces.

• Ureteroscopy: Uses a tiny camera to locate and remove or break stones.

• Percutaneous nephrolithotomy: A surgical procedure for very large stones, sometimes with a laser to break them apart.

How can you prevent kidney stones?

You can lower your risk by:

• Drinking 6–8 glasses of water every day

• Choosing citrus drinks like lemonade or orange juice, which help prevent crystal formation

• Reducing salt and animal protein intake

• Avoiding foods high in oxalates (like spinach, nuts, and rhubarb) if you’ve had calcium oxalate stones before

• Taking medications prescribed for your stone type, such as potassium citrate or allopurinol

For related conditions, see how alcohol affects your kidneys and increases the risk of stone formation.

Who is at risk?

You may be more likely to develop kidney stones if you:

• Do not drink enough fluids

• Have obesity or digestive problems

• Eat a diet high in salt, sugar, or animal protein

• Have a family history of kidney stones

• Live with conditions such as gout or recurrent urinary infections

• Take certain medications, such as diuretics or calcium-based antacids

Since high blood sugar can increase the risk of kidney stone formation, see understanding high glucose in urine.

How are kidney stones diagnosed?

Doctors may use:

• Blood and urine tests to check mineral levels

• Imaging scans (X-rays or CT scans) to locate and measure stones

• Stone analysis to determine what type you have and how to prevent more

And for simple multi-parameter tracking at home, try the Ribbon Checkup urine test to monitor changes that may signal kidney or urinary problems early.

When should you see a doctor?

See a doctor right away if you:

• Have severe pain that does not improve

• Notice blood in your urine

• Develop fever and chills with urinary symptoms

• Cannot pass urine

Ignoring kidney stones can lead to infections, kidney damage, or even kidney failure.

Key takeaway

Kidney stones may be small, but their effects can be serious. Understanding the types, causes, and treatments helps you take control of your kidney health. Staying hydrated and making simple lifestyle changes can make a big difference.

If you notice symptoms, don’t wait, talk to your doctor for diagnosis and treatment.

Take control of your kidney health with the Ribbon Checkup At-Home urine Test.

 

References

• American Kidney Fund. (2023). Kidney stones: Symptoms, causes, treatment and prevention. https://www.kidneyfund.org/living-kidney-disease/kidney-stones 

• American Urological Association. (2019). Medical management of kidney stones: AUA guideline. https://www.auanet.org/guidelines-and-quality/guidelines/kidney-stones-medical-management-guideline 

• Cleveland Clinic. (2022). Kidney stones: Causes, symptoms, diagnosis & treatment. https://my.clevelandclinic.org/health/diseases/15604-kidney-stones 

• European Association of Urology. (2023). EAU guidelines on urolithiasis. https://uroweb.org/guidelines/urolithiasis 

• Johns Hopkins Medicine. (2023). Kidney stones. https://www.hopkinsmedicine.org/health/conditions-and-diseases/kidney-stones 

• Mayo Clinic. (2023). Kidney stones: Symptoms and causes. https://www.mayoclinic.org/diseases-conditions/kidney-stones

• MedlinePlus. (2021). Kidney stones. U.S. National Library of Medicine. https://medlineplus.gov/kidneystones.html 

• Mount Sinai Health System. (2022). Kidney stones information. https://www.mountsinai.org/health-library/diseases-conditions/kidney-stones 

• National Health Service. (2022). Kidney stones. https://www.nhs.uk/conditions/kidney-stones

• National Institute of Diabetes and Digestive and Kidney Diseases. (2020). Kidney stones. U.S. Department of Health and Human Services. https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones 

 

Frequently Asked Questions

Q: What do kidney stones look like?

A: Kidney stones can be smooth or jagged, small like grains of sand or larger, and are usually yellow or brown.

Q: Can kidney stones pass on their own?

A: Yes, small stones may pass naturally with hydration, but larger ones often need medical treatment.

Q: What is the main cause of kidney stones?

A: Dehydration and high levels of minerals like calcium or uric acid in urine are common causes.

Q: How can kidney stones be prevented?

A: Drink plenty of water, reduce salt and animal protein, and avoid high-oxalate foods if prone to calcium oxalate stones.

Q: When should I see a doctor for kidney stones?

A: Seek medical help if you have severe pain, blood in urine, fever, or difficulty urinating.