What’s a kidney stone?
A stone in your kidney is an irregularly-shaped solid mass or crystal that can be as small as a grain of sand up to the size of a golf ball. Depending on the size of your kidney stone (or stones), you may not even realize that you have one. Even small stones can cause extreme pain as they exit your body through your urinary tract. Drinking fluids may help the process, which can take as long as three weeks.
A large kidney stone can get trapped in your ureter (the tube that drains urine from your kidney down to your bladder). When this happens, the stone can cause bleeding and keep urine from leaving your body. You may need surgery for a stone that can’t pass on its own.
How common are kidney stones?
Researchers have concluded that about one in ten people will get a kidney stone during their lifetime. Kidney stones in children are far less common than in adults but they occur for the same reasons. They’re four times more likely to occur in children with asthma than in children who don’t have asthma.
Who’s most likely to get kidney stones? What are the risk factors?
White men in their 30s and 40s are most likely to get kidney stones. However, anyone can develop kidney stones.
There are several risk factors for developing kidney stones. These include:
- Not drinking enough liquids.
- Having a diet that includes the substances that form the stones (phosphate, for example, is in meat, fish, beans and other protein-rich foods).
- Having a family history of kidney stones.
- Having a blockage in your urinary tract.
Certain medical conditions can also increase your risk of developing stones. This is because they may increase or decrease levels of the substances that make up a kidney stone. These conditions can include:
- Hypercalciuria (high calcium levels in your urine).
- High blood pressure.
- Gout and cystic fibrosis.
- Kidney cysts.
- Parathyroid disease.
- Inflammatory bowel disease and chronic diarrhea.
- Some surgical procedures, including weight loss surgery or other stomach or intestine surgeries.
Some medications can increase your risk of developing a stone. These medications include:
- Diuretics (water pills).
- Calcium-based antacids (used to treat osteoporosis).
- Crixivan® (used to treat HIV infections).
- Topamax® and Dilantin® (used to treat seizures).
- Cipro® (ciprofloxacin, an antibiotic).
- Ceftriaxone (an antibiotic).
Certain foods can also place you at risk of a kidney stone. These foods include:
- Meats and poultry (animal proteins).
- Sodium (diets high in salt).
- Sugars (fructose, sucrose and corn syrup).
Are kidney stones genetic (hereditary)?
Yes, kidney stones can run in families.
What’s the urinary tract? How does it work?
Your urinary tract is vital to your body because it gets rid of waste and extra fluid. It’s made up of both your kidneys, two ureters, your bladder and your urethra. Each organ has an important job (in the following order):
- Kidneys: Your fist-sized, bean-shaped kidneys are located on either side of your spine, below your rib cage. Each day they filter 120 to 150 quarts of your blood to remove waste and balance fluids. Your kidneys make one to two quarts of urine every day.
- Ureters: After your kidney creates urine, the liquid travels through the tube-shaped ureter to the bladder. There is one ureter per kidney. Kidney stones can pass through the ureters or, if they’re too big, get stuck in them. You may require surgery if the stone is too large.
- Bladder: Between your hip bones is your bladder, an organ that stores urine. It stretches to hold about one and a half to two cups.
- Urethra: Like a ureter, your urethra is a tube through which urine passes. It’s the final stop of the urinary tract where your urine (and a kidney stone) leaves your body. This is called urination.
How long does it take a kidney stone to form?
You can have kidney stones for years without knowing they’re there. As long as these stones stay in place within your kidney, you won’t feel anything. Pain from a kidney stone typically starts when it moves out of your kidney. Sometimes, a stone can form more quickly — within a few months.
Talk with your healthcare provider about your risk factors. They might do a 24-hour urine test to check how quickly you develop stones.
What are the most common types of kidney stones?
The most common type of kidney stone is a calcium oxalate stone. This type happens when calcium and oxalate combine in your urine. It can happen when you have high quantities of oxalate, low amounts of calcium and aren’t drinking enough fluids.
Stones caused by uric acid are also fairly common. These come from a natural substance called purine, which is a byproduct of animal proteins (meat, chicken and fish).
If I have multiple kidney stones, are they all made of the same substances?
The materials that make up a kidney stone can be different. You could develop a calcium oxalate stone and one made of uric acid.
Symptoms and Causes
What causes kidney stones?
Kidney stones are formed from substances in your urine. The substances that combine into stones normally pass through your urinary system. When they don’t, it’s because there isn’t enough urine volume, causing the substances to become highly concentrated and to crystalize. This is typically a result of not drinking enough water. The stone-forming substances are:
These and other chemicals are some of the waste products that exit your body.
What are the symptoms of kidney stones?
You can have a stone in your kidney for years and not know it’s there. But, when it starts to move or becomes very large, you may have symptoms. Symptoms of a kidney stone include:
- Feeling pain in your lower back or side of your body. This pain can start as a dull ache that may come and go. It can also become severe and result in a trip to the emergency room.
- Having nausea and/or vomiting with the pain.
- Seeing blood in your urine.
- Feeling pain when urinating.
- Being unable to urinate.
- Feeling the need to urinate more often.
- Fever or chills.
- Having urine that smells bad or looks cloudy.
Smaller kidney stones may not cause pain or other symptoms. These “silent stones” pass out of your body in your urine.
What are the symptoms of kidney stones in children?
The most common symptoms of kidney stones are blood in the urine or pain. The amount of pain your child experiences and where it hurts depends on where the stone is located and its size. Other symptoms include:
- Severe colicky pain.
- Inability to urinate (when a stone blocks the urinary tract).
- Cloudy, foul-smelling urine, fever, chills or weakness which might be a sign of a serious infection.
- Blood in the urine.
Most pediatric kidney stones remain in the kidney, but up to a third may migrate from the kidney and get stuck in a ureter. Stones that remain in the kidney, although often painless, can be the source of recurrent urinary tract infections. Those that lodge in the ureter can create severe colicky pain.
Diagnosis and Tests
How are kidney stones diagnosed?
Your healthcare provider will discuss your medical history and possibly order some tests. These tests include:
- Imaging tests: An X-ray, CT scan and ultrasound will help your healthcare provider see the size, shape, location and number of your kidney stones. These tests help your provider decide what treatment you need.
- Blood test: A blood test will reveal how well your kidneys are functioning, check for infection and look for biochemical problems that may lead to kidney stones.
- Urine test: This test also looks for signs of infection and examines the levels of the substances that form kidney stones.
Management and Treatment
How are kidney stones treated?
Once diagnosed, your healthcare provider will first determine if you even need treatment. Some smaller kidney stones may leave your system when you urinate. This can be very painful. If your provider decides that you do need treatment, your options include medications and surgery.
Medications. Medications may be prescribed to:
- Decrease pain. Your healthcare provider may recommend that you take an over-the-counter medication like ibuprofen or, if you’re in the emergency room, an IV narcotic.
- Manage nausea/vomiting.
- Relax your ureter so that the stones pass. Commonly prescribed medicines include tamsulosin (Flomax®) and nifedipine (Adamant® or Procardia®).
You should ask your healthcare provider before you take ibuprofen. This drug can increase the risk of kidney failure if taken while you’re having an acute attack of kidney stones — especially in those who have a history of kidney disease and associated illnesses such as diabetes, hypertension and obesity.
Surgery. There are four types of surgeries used to treat kidney stones. The first three are minimally invasive, meaning that the surgeon enters your body through a natural opening (like your urethra), or makes a small incision.
- Ureteroscopy: To perform this procedure, a small instrument called an ureteroscope is inserted in your urethra, through your bladder and into a ureter. This instrument shows the kidney stones and then retrieves them in a surgical “basket,” or breaks them apart using a laser. These smaller pieces of the kidney stones are then easily able to exit your body through your urinary tract.
- Shockwave lithotripsy: In this procedure, you’re placed on a special type of surgical table or tub. High-energy shockwaves are sent through water to the stone(s). The shockwaves break apart the stones, which are then more easily able to exit your body.
- Percutaneous nephrolithotomy: When kidney stones can’t be treated by the other procedures — either because there are too many stones, the stones are too large or heavy or because of their location — percutaneous nephrolithotomy is considered. In this procedure, a tube is inserted directly into your kidney through a small incision in your back. Stones are then disintegrated by an ultrasound probe and suctioned out so that you don’t have to pass any fragments. A urethral stent is placed after the procedure (an internal tube from the kidney to the bladder which is removed one week later). Patients are typically kept overnight for observation.
- Open stone surgery: A longer cut is used during this surgery. Compared to minimally invasive procedures, it’s rarely performed (0.3% to 0.7% of cases).
How are children treated for kidney stones?
Most children’s kidney stones can be treated with the shock wave lithotripsy (SWL), a completely non-invasive procedure. Your child is placed under anesthesia and sound waves of specific frequencies are focused on the stones to shatter them into fragments small enough to be easily passed during urination.
How long does it take to pass a kidney stone?
The amount of time it can take for you to pass a kidney stone is different from another’s. A stone that’s smaller than 4 mm (millimeters) may pass within one to two weeks. A stone that’s larger than 4 mm could take about two to three weeks to completely pass.
Once the stone reaches the bladder, it typically passes within a few days, but may take longer, especially in an older man with a large prostate. However, pain may subside even if the stone is still in the ureter, so it’s important to follow up with your healthcare provider if you don’t pass the stone within four to six weeks.
Are there any foods or drinks that help treat kidney stones? Are there any home remedies?
There are three liquids rumored to help with kidney stones:
- Cranberry juice. Although cranberry juice can help prevent urinary tract infections (UTIs), it doesn’t help with kidney stones.
- Apple cider vinegar. Vinegar is acidic and it can sometimes create changes to your urine, which helps with kidney stones. But, this doesn’t always help. Talk to your healthcare provider about the use of vinegar.
- Lemon juice. Lemon juice is rich in citrate, which can help prevent kidney stones from forming. Citrates are found in several citrus fruits including lemons, limes, oranges and melons.
- Coffee. Studies show that coffee may decrease your risk of developing kidney stones.
Avoid soda and other drinks with added sugar or fructose corn syrup. They increase your risk.
How can I prevent kidney stones?
There are several ways to decrease your risk of kidney stones, including:
- Drink water. Drink at least six to eight 8-ounce glasses every day (about 64 ounces). Staying hydrated helps you urinate more often, which helps “flush away” the buildup of the substances that cause kidney stones. If you sweat a lot, be sure to drink even more.
- Limit salt. Eat less sodium. You may want to connect with a dietician for help with planning what foods you eat.
- Lose weight. If you’re overweight, try to lose some pounds. Talk to your healthcare provider about an ideal weight.
- Take prescriptions. Your healthcare provider may prescribe some medications that help prevent kidney stones. The type of medication may depend on the type of stones you get.
Should I cut calcium out of my diet if I develop calcium oxalate kidney stones?
If you develop kidney stones composed of calcium, you may be tempted to stop eating foods that include calcium. However, this is the opposite of what you should do. If you have calcium oxalate stones, the most common type, it’s recommended that you have a diet higher in calcium and lower in oxalate.
Foods that are high in calcium include:
- Cow’s milk.
- Calcium-fortified juices.
- Dried beans.
- Calcium-fortified hot cereal.
Foods that are high in oxalates include (reduce these in your diet):
- Dried peas and beans.
- Nuts and nut butters.
- Wheat bran.
It’s also important to drink plenty of fluids to dilute the substances in your urine.
Outlook / Prognosis
What’s the outlook for kidney stones?
The outlook for kidney stones is very positive, although there is a risk of recurrence (the stones coming back). Many kidney stones pass on their own over time without needing treatment. Medications and surgical treatments to remove larger kidney stones are generally very successful and involve little recovery time.
It’s possible to get kidney stones multiple times throughout your life. If you keep developing kidney stones, your healthcare provider may work with you to discover why the stones happen. Once the cause is found, you may be able to make dietary changes to prevent future stones.
Can a large kidney stone cause an injury?
Your risk of injury from a kidney stone can go up based on the size and location of the stone. A larger stone could get stuck in a ureter, causing pressure to build up. This can lead to renal failure and, in the worst-case (but rare) scenario, you could lose your kidney. The chance of passing a 1 cm stone is less than 10%, and stones larger than 1 cm typically don’t pass.
How long does the pain last after you pass a kidney stone?
Pain from a stone can persist for a few days after completely passing. But, if the pain persists beyond a week, a repeated imaging test (usually an ultrasound) is done to see if any further blockage is present (sometimes due to a remaining stone fragment).
Can I live a normal life with kidney stones?
Kidney stones shouldn’t stop you from going about your daily activities, or drastically reduce your quality of life. Thanks to passing them while you urinate, and thanks to treatment options, kidney stones are not permanent.
Do kidney stones cause kidney disease?
If you’ve had kidney stones, you’re at a higher risk for more kidney stones and chronic kidney disease.
Are kidney stones deadly?
No. Kidney stones do not cause death.
When should I see my healthcare provider?
Don’t hesitate to see your healthcare provider if you’re experiencing symptoms of kidney stones. If you have a kidney stone, you’ll need to know where it’s located and what size it is so that you can get treatment and prevent complications.
When should I go to the emergency department?
Go to the emergency department if the pain is unbearable. You may be prescribed medication for your pain and any nausea/vomiting.
What questions should I ask my healthcare provider?
- Do I have a kidney stone or is there another reason for my symptoms?
- What type of kidney stone do I have?
- What size is my kidney stone?
- Where is my kidney stone located?
- How many kidney stones do I have?
- Do I need treatment or will I be able to pass the kidney stone?
- Should I be tested for kidney disease?
- What changes should I make to my diet?
- What type of procedure should I have to get rid of the stones?
A note from Cleveland Clinic
Kidney stones can be frustrating at best and agonizingly painful at the worst. To stop your situation from getting worse, you should be evaluated by a healthcare provider as soon as possible. The pain can get severe, and surgery might be necessary. Remember: don’t skip your prescriptions, drink lots of water and follow any dietary guidelines. Also, remember that kidney stones are a temporary condition. They won’t bother you forever.