How to prevent kidney stones: 4 simple steps to lower your risk

Kidney stones are more common than you might think. About 11% of men and 6% of women in the United States have a kidney stone at least once during their lifetime. For some people, a small stone passes with little trouble, while for others, a stone can cause sudden, intense pain in the back, side or abdomen that sends you looking for answers.

Understanding what causes kidney stones, what they feel like and how to prevent kidney stones can help you know what to do if you develop one.

Let’s take a closer look.

What are kidney stones?

Kidney stones are hard, pebble-like pieces of material that form inside your kidneys when certain minerals and salts in your urine become too concentrated. They can be as small as a grain of sand or much larger.

Some stones stay in the kidney and cause few or no symptoms, while others move into the ureter, the narrow tube that carries urine from your kidney to your bladder. That is when you may experience the sudden, intense discomfort often associated with kidney stones.

Dehydration is one of the biggest risk factors for developing kidney stones, because having less fluid in your urine makes it more concentrated. Your risk can also be higher if you have had a kidney stone before or have a family history of them.

Your diet and certain health conditions can also affect your risk. Eating a lot of sodium or animal protein can increase the chance of certain types of stones. Some people are also more likely to form stones because of how their bodies process calcium, oxalate (oxalic acid) or uric acid. 

4 types of kidney stones

There are four main types of kidney stones, and knowing which type you have can help explain why it formed and how to lower your risk of another one.

1. Calcium stones are the most common type of kidney stone. They are usually made of calcium oxalate, although some contain calcium phosphate. Several factors can contribute to these stones, including diet, genetics and certain health conditions. A diet high in sodium (salt) can increase calcium in your urine, while not getting enough calcium from food can increase the amount of oxalate your body absorbs.
2. Uric acid stones form when your urine contains too much uric acid. They are more likely in people who eat large amounts of animal protein or have certain health conditions, including gout and diabetes.
3. Struvite stones are less common and are usually linked to certain urinary tract infections. They can grow quickly and sometimes become quite large.
4. Cystine stones are rare and occur in people with cystinuria, an inherited condition that causes the kidneys to release too much of the amino acid cystine into the urine.

What do kidney stones feel like?

The first signs of a kidney stone tend to appear when it moves from your kidney into your ureter. A stone can irritate the ureter or block the flow of urine, causing discomfort. 

Kidney stone pain is described as sharp and severe and can change as the stone travels through your urinary tract. You may feel it in your back or side below your ribs, or it could move toward your lower abdomen or groin. The pain may come in waves as the stone moves.

Other kidney stone symptoms include:

• Pain or burning when you urinate
• A frequent or urgent need to urinate
• Urinating only a small amount
• Pink, red or brown urine caused by blood
• Nausea or vomiting
• Cloudy or foul-smelling urine

Kidney stone pain vs. a muscle spasm or UTI

Sudden flank or lower back pain does not always mean you have a kidney stone. There are other conditions that present similarly to a kidney stone. Because several conditions cause similar symptoms, a urine test, blood test or imaging can help determine what is causing your pain.

• Muscle strains and spasms can lead to pain in your back or side, particularly after lifting, exercising or making an awkward movement.
• A urinary tract infection (UTI) can cause burning with urination, frequent urination and discomfort in the lower abdomen. Fever and chills can be signs of an infection and deserve medical attention, particularly when they occur with symptoms that could indicate a blocked urinary tract.
• Appendicitis can also cause abdominal pain that may initially be difficult to pinpoint. The pain often becomes more focused in the lower right abdomen, although symptoms vary.

How long does it take to pass a kidney stone?

Once it’s been determined you have a kidney stone, the likely next question is “how long does it take to pass a kidney stone?” The answer is that there is no single timeline that applies to everyone. A small stone may pass within days, while another can take several weeks. The size and location of the stone can give your doctor a better idea of what to expect.

Studies have found that smaller ureteral stones are more likely to pass on their own. In one study, 95% of stones measuring 2 to 4 millimeters passed spontaneously, although it could take as long as 40 days. Larger stones were less likely to pass without intervention. 

What can you do while waiting for a kidney stone to pass?

If you have been told that your stone is small enough to pass on its own, follow the instructions you were given by your doctor for managing it at home. Be sure you are drinking fluids, taking any recommended pain medicine and straining your urine so the stone can be collected for analysis.

Drinking enough fluid helps keep your urine diluted, but forcing yourself to drink very large amounts of water at once will not necessarily make a stone pass faster. If you are vomiting or cannot keep fluids down, you may become dehydrated and will need medical care. 

When to seek care for kidney stone symptoms

Some kidney stones can be monitored at home with guidance from your doctor, but in other cases, certain symptoms call for prompt evaluation, which also helps rule out other causes like appendicitis or a UTI.

Seek medical care if you have the following symptoms associated with kidney stones. They can signal an infection, dehydration or an obstruction that needs treatment.

• Severe or worsening pain
• Pain occurring with fever or chills
• Repeated vomiting
• Difficulty urinating
• Blood in your urine

How are kidney stones treated?

Kidney stone treatment depends on factors such as the stone's size, location and composition, along with your symptoms and whether the stone is blocking urine flow.

A small stone that is likely to pass may be monitored while you manage discomfort and other associated symptoms.

Larger stones or stones that cause significant blockage, ongoing symptoms or other complications may require a procedure. Depending on the situation, treatment may involve breaking the stone into smaller pieces or removing it. 

If you pass a stone, your doctor might recommend having it analyzed. Blood and urine testing also help identify factors that contribute to your kidney stone formation.

4 ways to prevent kidney stones

If you have had a kidney stone, prevention becomes especially important because you can develop another one. The best approach depends on why the kidney stone formed in the first place and what type it was. There are several things you can do to help prevent kidney stones or lower your risk of developing another one.

1. Drink enough water (preventing dehydration)

Drinking enough fluid, mainly water, is one of the most important things you can do to prevent kidney stones.

Staying well hydrated helps your kidneys do their job by helping flush waste from your body through urine. It also supports healthy blood pressure and helps maintain the right balance of electrolytes, including sodium, potassium and calcium. More fluid means more diluted urine, which makes it harder for stone-forming minerals to build up. 

Your fluid needs increase when you exercise, work outside or spend time in hot weather. Ensuring you drink enough water is especially important during a hot Texas summer or after a workout when you are losing fluid through sweat.

The recommended daily fluid intake guidance for adults is approximately 8 to 12 (8-ounce) cups. However, if you have been told to restrict fluids because of another health condition, follow that guidance rather than increasing your intake on your own.

Recommended fluids to prevent kidney stones include:

• Water
• Cow’s milk
• Plant-based milks (oat, almond, coconut)
• Unsweetened sparkling water
• Unsweetened fruit juice
• Coffee or tea without added sugar

Try to avoid consuming soda, energy drinks, alcohol and high-sugar drinks like lemonade or sweet tea.
 

Related: Hydration hacks: Fun, innovative ways to boost your water intake

2. Watch your sodium intake

Eating a lot of sodium can increase the amount of calcium released into your urine, which can contribute to calcium-containing kidney stones.

Much of the sodium in your diet comes from packaged foods, fast food, canned foods, processed meats, sauces and other prepared foods. Checking nutrition labels and preparing more meals at home can make it easier to keep your sodium intake in check.

The American Heart Association recommends aiming for less than 2,300 milligrams (mg) of sodium a day. 

3. Get enough calcium from food

People with calcium kidney stones should NOT be on a low-calcium diet.

Calcium in the foods you eat binds with oxalate in your digestive tract, helping keep oxalate from being absorbed into your bloodstream and eventually reaching your urine. When you do not get enough dietary calcium, more oxalate can be absorbed and excreted in your urine, where it can combine with calcium and contribute to calcium oxalate stones.

Getting the recommended amount of calcium from food can actually help prevent oxalate from being absorbed in the digestive tract and entering the urine. The National Kidney Foundation suggests you aim for 1,000 - 1,200 mg calcium per day, or 2 to 3 servings of dairy per day with meals.

It’s always a good idea to talk with your doctor about how much calcium you need and whether calcium supplements are appropriate for you.

4. Pay attention to animal protein

Eating large amounts of animal protein can increase the risk of certain kidney stones, but you do not need to fully eliminate protein from your diet. Depending on the type of stone you form, you may be advised to moderate high-protein foods such as beef, pork, poultry, fish and eggs.

Your doctor or a dietitian can help you determine how much protein you need and whether shifting some of your protein choices toward plant-based foods such as whole grains, beans, nuts and seeds makes sense for you. 

A plan to prevent kidney stones in the future

A kidney stone can be an uncomfortable reminder to pay closer attention to your hydration, diet and individual risk factors. Learning how to prevent kidney stones starts with understanding why you formed one in the first place.

If you are currently experiencing sudden flank or abdominal pain, pay attention to what else is happening. Kidney stone symptoms can overlap with other causes of abdominal pain.

And if you have already passed a stone, ask what type it was and whether additional testing could help explain why it formed. That information can give you a more useful kidney stone prevention plan for the future.

Looking for specialized care for kidney-related concerns? Connect with your doctor or a urologist today.