Kidney stones are hard pebble-like objects that can form inside your kidneys. They’re made of minerals and salts. You might hear your doctor call them renal calculi, nephrolithiasis, or urolithiasis.
Kidney stones are small — usually between the size of a kernel of corn and a grain of salt. They can form when your body has too much of certain minerals, and at the same time doesn’t have enough liquid. The stones can be brown or yellow, and smooth or rough.
You can have kidney stones and not have any symptoms. Or the symptoms may not start until your kidney stone goes on the move.
A stone can move around within your kidney. It can also move into the tube that connects your kidney to your bladder. Symptoms can be mild or strong, and include:
When to call a doctor
If you’re in really bad pain, you’ll probably want to see a doctor. Other signs you should quickly seek medical care include:
Both men and women can get kidney stones, but men’s chances of getting them are about double that of women’s.
It’s often hard to figure out what caused a kidney stone. But they happen when your urine has high levels of certain minerals. These include:
If you don’t have enough urine in your body to water down the high concentration of minerals, stones can form. Think about stirring up your favorite drink from a powder mix. If you don’t add enough liquid — say, water or juice — the powder will clump up and turn into hard, dry chunks.
Things that can raise your risk for kidney stones include:
Things that can cause kidney stones include:
Doctors break down kidney stones into types. Knowing which kind you have could affect the treatment you get. They include:
Calcium stones: These are the most common ones. Even just eating some foods very high in oxalates, such as rhubarb, or taking unusually high levels of vitamin D, can boost your chances of getting this type. You could get this kind if you typically don’t drink enough water or if you sweat a lot and don’t replace the fluids you lose.
Cystine stones: This is the least common type and due to a genetic mutation. In this situation, your kidneys have trouble reabsorbing a compound called cystine, which ends up in the urine at higher levels and causes stones to form.
Struvite stones: Infections, especially in the urinary tract, can cause this kind of stone.
Uric acid stones: Eating large amounts of animal proteins can lead to uric acid buildup in your urine. That can eventually form a stone either with or without calcium. Risk factors include gout, diabetes, and chronic diarrhea.
How does your doctor know if you really do have a kidney stone? First, they’ll get a medical history and examine you. Then, if needed, they’ll order tests to get pictures of your kidneys and urinary tract.
You might get:
Pregnant women should get an ultrasound rather than a CT scan in the first trimester, when babies are most at risk of a radiation injury. A low-dose CT scan is less dangerous in the second and third trimesters.
Not all kidney stones require treatment. If a stone is small, you may be able to get rid of it when you pee. To speed up the stone’s passage, you can:
The doctor may want you to save the stone so it can be tested. Knowing what kind of stone it is may help prevent you from having another one.
If your stone is bigger or you can’t pass it, you might be in a fair amount of pain. In this case, the doctor can break up the stone in a couple of ways, so your body can eventually get rid of it. These include:
Extracorporeal shock wave lithotripsy (ESWL): This is the most common procedure for kidney stones in the United States. It uses shock waves, which can blast the stone into little pieces. Then, the smaller pieces can more easily be passed in your urine.
The treatment takes about an hour, and you can usually go home about an hour later. It doesn’t involve any surgical cuts, but there’s still some pain. Your doctor will talk about your options with you: sedation, local anesthesia (you’re given something to numb the pain but stay awake), and general anesthesia (you’re not awake during the procedure).
Ureteroscopy: This procedure treats stones in your kidneys and ureters. The doctor uses a thin, flexible scope to find and remove stones. They won’t make any cuts in your skin, but you will be asleep during this procedure.
The doctor will pass the scope through your bladder and ureter into your kidney. They’ll use a small basket to remove small stones. If the stones are larger, the doctor will pass a laser through the scope to break them up. Most people go home the same day.
Percutaneous nephrolithotomy: Another way doctors can get rid of a kidney stone is to cut a small hole in your back and through your kidney in order to remove the stone. If this procedure is done, you could have to stay in the hospital for several days.
Once you have a kidney stone, you’re more likely to get one later in life. About half of people who have one will get another within 7 years if they don’t take care to try to prevent it. To stop this from happening, you can:
Drink plenty of water: You should drink at least eight 8-ounce glasses of water each day. Some of that liquid can be orange juice, lemonade, or limeade.
Cut back on sodium and salty foods: Lots of sodium can raise calcium levels in your urine. That can cause stones to form. If you cut back on the sodium you get from food and beverages, it also will help your heart and lower your blood pressure.
Drink and eat enough calcium: This preventive step might sound a little confusing, as doctors will tell you that high calcium levels (because of too much sodium) in your urine can cause a stone. Not getting enough calcium can boost the level of the oxalates in your urine. They’re found in foods like rhubarb, spinach, beets, bran flakes, potato chips, and french fries. And oxalates can cause kidney stones. It’s best to get your calcium from foods and beverages rather than supplements.
Avoid certain foods and soft drinks: If you’ve already had at least one kidney stone, it’s a good idea to limit the animal protein you eat each day to a piece about the size of a deck of cards. Some foods, such as eggs, spinach, beets, chocolate, and nuts, as well as colas, have been linked to kidney stones.
Consider alkali citrate therapy: Taking alkali citrate (either in the form of lemon juice or supplements) can help prevent future stones. Citrate binds to calcium in the urine, preventing it from binding to other particles (such as oxalate and phosphate), which are what most stones are made of. Please consult with your doctor before starting any treatment.”
Complications can follow treatment for a large kidney stone or result from leaving stones untreated. They can include:
SOURCES:
National Institute of Diabetes and Digestive and Kidney Diseases: “Kidney Stones in Adults.”
National Kidney Foundation: “Kidney Stones,” “Kidney Stone Diet Plan and Prevention,” “Medullary Sponge Kidney.”
The Mayo Clinic: “Diseases and Conditions: Kidney Stones,” “Inflammatory bowel disease (IBD),” “Triamterene And Hydrochlorothiazide (Oral Route).”
Urology Care Foundation, the Official Foundation of the American Urological Association: “Pregnancy and Kidney Stones,” “What are Kidney Stones?”
Harvard Health Publications, Harvard Medical School: “5 steps for preventing kidney stones,” “Kidney stones: Common, painful, preventable.”
University of Chicago: “Types of Kidney Stones: A Primer.”
National Organization for Rare Disorders: “Dent Disease.”
Kettering Health Network: “What You Should Know About Kidney Stones.”
UW Health: “Medication Contributors to Kidney Stones.”
FDA: “Crixivan.”
UpToDate: “Nephrolithiasis during pregnancy.”
University of California, San Francisco: “Parathyroidectomy.”
National Health Service: “Treatment: Kidney Stones.”
InformedHealth.org: “Kidney Stones: Overview.”
How you can prevent them.
What to expect.
How to know if you have kidney stones.
How are they different from kidney stones?
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