What Are Kidney Stones?
Kidney stones are common. They form in the kidneys and may move through the urinary tract.
Men are more likely than women to get kidney stones.
You're at greater risk if someone in your family has kidney stones or if you've had them before.
About the kidneys
Your kidneys are part of your urinary tract. These fist-sized organs sit below your rib cage on either side of your spine.
Your kidneys act as filters that remove waste from your body.
After your kidneys filter your blood, excess water and chemicals make a liquid waste product called urine or pee. Pee moves through your urinary tract constantly.
Besides the kidneys, the urinary tract includes your:
- Bladder. The hollow muscular organ that holds pee.
- Ureters. Two thin tubes that move pee from the kidneys to the bladder.
- Urethra. The tube that pee travels to leave your body.
What Causes Kidney Stones?
Kidney stones form when the chemicals in your pee make crystals that join and form a hard, stone-like piece.
Different chemicals cause different types of stones:
- Calcium oxalate. When calcium (a mineral) and oxalate (a compound) found in urine combine, calcium oxalate stones can form. These are the most common type of kidney stones.
- Uric acid. When a blood waste product called uric acid builds up in the kidneys, uric acid crystals form. Uric acid may build up if you eat a high-purine diet found in foods such as organ meats, sardines, and anchovies. Uric crystals form another common type of kidney stone.
- Struvite. Struvite is a substance that forms when you have a kidney infection or infection in the ureters (the upper urinary tract). Struvite stones sometimes stay in the kidney or move to the ureters.
- Cystine. Cystine is an amino acid that builds up in the pee if you have a rare genetic condition called cystinuria. This type of kidney stone is rare.
What Are the Risk Factors for Kidney Stones?
The foods you eat and the liquids you drink can increase your risk of getting certain kidney stones.
Kidney stones can form when you consume too much:
- Animal protein, including meat, eggs, milk, and cheese.
- Fish or shellfish.
- Fructose, a type of sugar found in fruit.
- Leafy greens, such as spinach.
- Organ meats, like liver and kidney.
- Salt or sugar.
Kidney stones can also occur if you're dehydrated. To prevent dehydration:
- Aim to drink at least 64 ounces of water daily.
- Drink extra fluids if you exercise or live in a hot climate to help you stay hydrated.
You may have a higher risk of kidney stones if someone in your family has them.
You may also be more likely to get kidney stones if you have:
- Cystic kidney disease.
- Digestive diseases, such as gallstones or irritable bowel syndrome.
- High blood pressure.
- Hypercalciuria (too much calcium in your pee).
- Hyperoxaluria (too much oxalate in your pee).
- Hyperparathyroidism (too much parathyroid hormone, which creates extra blood calcium).
- Repeated UTIs.
What Are the Complications of Kidney Stones?
After you get one kidney stone, you're more likely to get another. Kidney stones may make you more likely to develop chronic kidney disease.
Left untreated, kidney stones can cause pain and infection, especially if you can't pass the stone when peeing. This can increase your chances of having blood in your urine.
How Do I Prevent Kidney Stones?
You can reduce your risk of kidney stones by:
- Staying at a healthy weight.
- Limiting the amount of sodium, animal protein, or calcium in the foods you eat. If you've already had a kidney stone, talk to your doctor about diet changes you should make.
- Staying well hydrated.
Talk to your doctor about your risk of kidney stones.
Why Choose UPMC Urology for Kidney Stone Care?
- Use advanced technologies to diagnose and treat kidney stones.
- Assess your kidney stone risk and relieve your pain as quickly as possible.
- Focus on restoring healthy urinary tract function and helping prevent kidney stones.
To make an appointment, contact a UPMC urologist near you.