What are early signs of kidney stones?

Early signs of kidney stones could be foul-smelling urine, the urge to pee often or difficulty peeing. Sometimes more severe signs may appear right away, like bloody urine, intense pain in your back or side, or nausea and vomiting.

What does a kidney stone look like?

Kidney stones look like crystalized stones. Picture small pebbles — some even look like tiny walnuts.

How long does it take to pass kidney stones?

Depending on the type and size, a kidney stone may pass within a few days or a few weeks. For kidney stones that are too large, you may need a procedure or surgery.

What is a kidney stone vs. a bladder infection?

Kidney stones and bladder infections share many of the same symptoms, like painful urination, pain in your mid-section and feeling the need to pee often. However, there are more symptoms with kidney stones and they’re much more painful. While antibiotics can treat most bladder infections, they can’t treat kidney stones.

What foods may help prevent kidney stones?

It may help to limit or avoid foods high in oxalates, like spinach, certain berries, chocolate, wheat bran, nuts and tea.

Kidney stones: symptoms, types and treatments

Kidney stones. They’re small, but they’re mighty. Did you know that more than half a million people head to the emergency room for kidney stones each year?¹ You may be wondering how something so little can be so painful. Most kidney stones range in size from a grain of sand to a chickpea. But rarely some can grow to be the size of a golf ball. Read on to learn what kidney stones are and what to know if you think you may have one.

What are kidney stones?

A kidney stone is a hard mass made up of minerals, salts and chemicals that form inside your kidneys. Specifically, these substances can be calcium, uric acid, xanthine. They’re all waste products that typically leave your body through urine. But if there’s not enough urine to help carry these waste products out of your body, they can concentrate and crystalize into a tiny little stone.²^,³

What are the types of kidney stones?

Depending on what it’s made of, kidney stones are classified into groups. This helps doctors determine why you got it in the first place and how you might be able to prevent future stones. So, if you pass a stone at home, save it for a doctor’s analysis. The different types of kidney stones are:^2,3

Calcium stone: This is the most common type of kidney stone. Calcium stones usually develop as calcium oxalate and they form when calcium and oxalate combine in your urine. Calcium oxalate stones are mainly linked to high levels of oxalate, low amounts of calcium and poor fluid intake. A second variation of calcium stones develop as calcium phosphate. These stones are often caused by metabolic conditions or certain medicines.
Uric acid stone: Uric acid stones form when you lose too much fluid (think dehydration). That could be from chronic diarrhea, malabsorption or simply not drinking enough water. It’s also common in people with a high-protein diet, metabolic conditions, diabetes or certain genetic factors.
Struvite stone: These stones are less common and form when there’s a urinary tract infection. They can grow quickly and may show little or no symptoms.
Cystine stone: This type of stone is rare and forms in people who have a hereditary condition called cystinuria. It causes your kidneys to release too much of a specific amino acid (cystine).

How are kidney stones diagnosed?

If your doctor thinks you might have a kidney stone based on your symptoms and physical exam, they’ll likely do tests to determine diagnosis.

Blood test: A blood test can tell your doctor if there’s too much calcium or uric acid in your blood, which may indicate the likelihood of a stone. Markers in your blood show your doctor how healthy your kidneys are and can help identify other medical conditions that might be related (or not) to your kidney stone.
Urine test: This 24-hour collection test could help show if you’re passing a lot of stone-forming minerals and/or not enough stone-preventing substances.
Imaging: Things like CT scans and ultrasounds can help spot kidney stones (even really small ones).

If you think you might be passing a stone, you’ll likely be asked to urinate through a strainer so you can catch it — even though it might feel a little odd to go to the bathroom with a strainer in hand. But it’s important for your doctor to check what your stone is made of so you can try to prevent future kidney stones.

What are the signs and symptoms of kidney stones?

If you’ve been lucky enough to have never experienced a kidney stone, you might remember less fortunate friends or family members say it was the worst pain of their lives. You may get pain in your abdomen, lower back and groin as the stone makes its way through your narrow ureter and eventually out of your body. A kidney stone may not cause symptoms unless it moves from your kidney and gets lodged in your ureter. There, it could block the flow of urine and cause your kidney to swell and spasm.³

Symptoms of kidney stones include:²^,³

Dull or sharp pain in your side, back, belly, groin or below your ribs
Trouble, pain or burning while you urinate
Feeling the need to urinate often or in small amounts
Bloody urine
Foul smelling or cloudy urine
Pink, red or brown urine
Nausea and vomiting

Keep in mind, kidney stone pain can move around as the stone moves. So, it’s common for the pain to travel around your mid-section and even change in intensity.

Am I at risk for kidney stones?

While men are more likely to get kidney stones, women can get them just as easily. Here are factors to be aware of:³

Family or personal history: Some stones could be hereditary, so if mom or dad has had a stone, you’re at a greater risk. Or, if you’ve had one before, you may likely get one again.
Dehydration: If you don’t drink enough water, you could be creating a comfortable home for a kidney stone to grow.
Certain diets and foods: Foods high in oxalate content (nuts, chocolate, certain fruits and vegetables), animal protein, along with sugar and sodium could increase your risk.
Obesity: Weight gain has been linked to kidney stones.
Digestive diseases and surgery: Things like gastric bypass surgery, inflammatory bowel disease or chronic diarrhea can increase your chances. Basically, anything that changes the way your body digests and absorbs calcium and water could increase the amount of stone-forming substances in your urine.
Certain medical conditions: Metabolic conditions (like diabetes and cystinuria) or any other factors that affect your body’s ability to metabolize food could increase your risk.
Certain supplements and medicines: High doses of vitamin C (your body breaks it down into oxalate), excessive use of laxatives, calcium-based antacids, and medicines used to treat depression or migraines could play a part in your risk for getting kidney stones.

Can I prevent kidney stones?

You may be starting to see a pattern with certain nutrients and minerals. Water, calcium and oxalate are big players in causing kidney stones. And, you’ve got control over how much goes in your body. Certain factors, like health history, isn’t something you can change, but lifestyle habits are. They’re actually pretty simple — take a look:^3,4

Reach for water. No matter if you sweat a lot, do hot yoga, sit in saunas or simply enjoy hot summer days, you have to hydrate your body. For those activities that make you lose water, they also make you urinate less, which means less waste leaves your body and those stone-forming substances have time to crystalize.
Watch your diet. You may want to consider limiting foods high in oxalate and sodium (salt), and avoiding high doses of vitamin C and calcium from supplements (unless recommended by your doctor). On the flipside, make sure you’re getting enough natural calcium from food sources. And, keep an eye on how much animal protein you eat — too much can cause calcium and uric acid to build up in your body.
Take a look at your medications. Do some research and talk to your doctor to see if any medicine you’re taking could cause kidney stones.

How are kidney stones treated?

Treatment for a kidney stone is typically necessary when the stone is too large to pass, if there's an infection, severe pain or if there's a risk to your kidney function. If that’s the case, you may need a procedure or even surgery. There are 4 things your doctor could do:⁵

Shock wave lithotripsy: This non-invasive treatment is the most common for small to medium-sized kidney stones in the U.S. It uses high-energy sound waves to break up your stone into smaller pieces (or even dust) so you can pass it.
Ureteroscopy: For this procedure, your doctor places a flexible scope through your urethra and into your ureter to reach the stubborn stone. If it’s small enough, the stone can be removed using a little basket. If not, your doctor can use a laser to break it up into smaller pieces.
Percutaneous nephrolithotomy/nephrolithotripsy: If the stone is too big to pass or both treatments aren’t recommended, your doctor can insert a thin tube through your back and into your kidney. Your doctor can either remove it through the tube (nephrolithotomy) or break it up and remove the stone dust (nephrolithotripsy). Don’t worry, you’re put under anesthesia for this one.
Open surgery: Rarely, if your stone is really big or other treatments didn’t work, you may need your doctor to remove your stone.

Who should I see if I'm concerned about kidney stones?

If you have any symptoms listed above, or you’re concerned about your chances of getting a kidney stone, visit your primary care provider (the doctor or provider you might see for your yearly physical). Bring a list of your symptoms, health history, concerns and questions. Depending on how the conversation goes, you may need diagnostic testing or you might be referred to a urologist.