How do you know if you have a kidney stone?

Sharp pain in your side or back, often below the ribs, that comes in waves and can spread to your lower belly or groin. You might also see blood in your urine, feel sick to your stomach, or need to pee more often than usual. Sudden pain that won't ease up, plus fever, means go to the ER (emergency room) right away.

Can I pass a kidney stone at home?

Yes, if the stone is small — under 4 millimeters, about the size of a grain of rice — most pass on their own within one to three weeks. Drink 2 to 3 liters of water a day and take an over-the-counter pain reliever like ibuprofen. Call your doctor if the pain worsens, you can't keep fluids down, or you get a fever.

What foods cause kidney stones?

No single food causes stones, but some raise your risk. High-oxalate foods (foods containing a natural plant compound called oxalate) like spinach, beets, and nuts can combine with calcium to form stones in people prone to them. Too much salt, red meat, and sugary soda also push up your odds. Cutting salt matters more than avoiding any one food.

Does drinking water dissolve kidney stones?

No, water won't dissolve a stone that's already formed. What it does is dilute your urine so minerals are less likely to clump into new stones, and it can help flush a small stone out faster. Aim for enough water that your urine looks pale yellow, roughly 2.5 liters a day.

Is kidney stone pain worse than labour (childbirth)?

Many women who've experienced both say stone pain hits harder in the first few minutes, though labour lasts longer overall. Stone pain comes in sudden, gripping waves as the stone moves through your ureter (the tube linking kidney to bladder). Pain intensity varies by person, so it's not really a fair comparison.

Will kidney stones come back?

Yes, about half of people who've had one stone get another within five to ten years. Your risk depends on the stone type, your diet, and how much water you drink daily. A doctor can test the stone to find out what caused it and build a plan to lower your odds of a repeat.

Should I avoid calcium if I get stones?

No, cutting calcium usually backfires. Calcium from food binds with oxalate (a compound found in many plants) in your gut before it reaches your kidneys, which actually lowers stone risk. Aim for 1,000 milligrams a day from foods like milk, yogurt, and cheese. It's calcium supplements taken without food, not dietary calcium, that raise your risk.

Kidney Stones: Causes, Symptoms & Foods | SpotMedics

What are kidney stones?

A kidney stone is a hard lump that forms inside your kidney (the organ that filters waste out of your blood). It's made of minerals and salts that stick together instead of passing out in your urine. Some stones stay tiny, like a grain of sand. Others grow as big as a marble.

This guide covers kidney stones causes, symptoms and foods to avoid, in plain language, so you know what's happening in your body and what to do next. We'll also look at how doctors in India diagnose and treat stones, what it costs, and how to stop them coming back.

Think of a stone like a tiny rock garden inside your kidney. It starts as one crystal. More crystals stick to it over time. A stone can be smooth or jagged. Jagged stones tend to hurt more. They scratch as they move.

How a stone forms

Your kidneys filter your blood all day. They remove waste and extra minerals like calcium and oxalate (a natural substance found in foods like spinach and nuts), and send them out in your urine¹.

Normally these waste products stay dissolved in water, just like sugar dissolves in tea. But if your urine gets too concentrated, or you have too much of certain minerals, they stop dissolving.

They start to stick together as tiny crystals. Over weeks or months, more crystals join in. Slowly, a stone builds up.

Most stones form quietly in the kidney and cause no trouble at first. The problem starts when a stone tries to travel out through your urinary tract (the pipes that carry urine from your kidney to your bladder and out of your body).

Picture a glass of sugar water left in the sun. As the water dries up, sugar crystals form at the bottom. Your urine works the same way. Less water means more crystals. That's why doctors keep coming back to one simple fix. Drink more water.

Why they hurt so much

Your ureter (the thin tube that connects each kidney to your bladder) is only about as wide as a pencil lead. A stone moving through it is like trying to push a pebble through a straw.

When a stone gets stuck, urine backs up behind it. The ureter squeezes hard, trying to push the stone along. That squeezing is what causes the intense pain people describe with kidney stones.

It's one of the most painful things a body can go through. Doctors sometimes compare it to labour pain. The pain comes in waves because your ureter is squeezing in waves, not staying tight all the time.

An attack can last minutes or hours. Some people get short bursts of pain that come and go all day. Others get one long, brutal wave. It doesn't let up until the stone moves. There's no way to predict which one you'll get. That's part of what makes a first attack so frightening.

What are the symptoms of a kidney stone?

Not every stone causes symptoms. A small stone sitting quietly in your kidney might never bother you. But once a stone starts moving, the signs are hard to miss.

The classic pain (renal colic)

Doctors call this pain renal colic (sudden, severe pain caused by a stone blocking urine flow)¹. It usually starts in your back or side, just below your ribs.

As the stone moves down the ureter, the pain often shifts. It can travel to your lower belly and groin. Men sometimes feel it in the testicle on the same side.

The pain comes in waves. It builds up, peaks hard, eases off a little, then builds again. Many people can't sit still during an attack. They pace, they curl up, they change position again and again looking for relief.

This is different from a muscle ache or backache from lifting something heavy. Renal colic is often sudden and severe, and it doesn't ease when you rest.

An attack often starts at night or early morning. It can wake you from sleep. Some people first mistake it for gas pain or a pulled muscle. Within an hour, the pain usually makes it clear this is something else. Here's a simple test. Ask if changing position helps. With a normal backache, lying still often eases things. With renal colic, no position feels comfortable for long.

Blood, nausea and urine changes

Along with the pain, you may notice blood in your urine. It can turn your urine pink, red or cola-coloured. Sometimes the blood is so small in amount you can't see it, and only a lab test picks it up.

Nausea and vomiting are common during a bad attack². Your body reacts to the intense pain the same way it might react to severe motion sickness.

You might also notice

A burning feeling when you pass urine
Needing to urinate more often than usual
Cloudy or bad-smelling urine
A small amount of urine each time, even though you feel the urge to go
Pain that eases a little right after you pass urine
A heavy or pressing feeling low in your belly

If you see pink or red urine, don't panic right away. It can look scarier than it is. Still, call your doctor the same day. If you can, take a quick photo of what you saw. It helps your doctor judge how much blood there was.

If you also get fever and chills along with these symptoms, that can mean infection has set in along with the stone. This needs urgent medical attention, not a wait-and-watch approach.

While you wait for help, small sips of water are fine, unless vomiting makes that hard. Some people find sitting or slow walking eases the pressure more than lying flat. Try to note the time your pain started. Your doctor will ask you this.

When a stone is silent

Some stones sit in the kidney for years without moving. These are called silent stones. You might only find out about one by accident, during a scan done for something else.

For example, someone might get an ultrasound for a stomach problem and spot a stone by chance. It causes no pain at all. That's why doctors call it silent. Even so, don't ignore it. A silent stone can grow bigger over months. A bigger stone is harder to pass later.

A silent stone doesn't always need treatment right away. But your doctor (a urologist, who specialises in the urinary system) will usually want to keep an eye on its size with repeat scans.

What causes kidney stones?

Kidney stones causes come down to one basic problem. Your urine has too much of certain minerals, and not enough water to keep them dissolved.

Not enough water

This is the single biggest cause. When you don't drink enough fluid, your urine becomes concentrated, like syrup instead of tea.

Concentrated urine makes it much easier for minerals to stick together and form crystals. This is why kidney stones are more common in hot climates and among people who work outdoors and sweat a lot without replacing the fluid.

Doctors generally recommend drinking enough fluid to pass about 2 litres of urine a day³. For most adults, that means roughly 2.5 to 3 litres of water daily, more if you sweat heavily.

A simple home check works well here. Look at your urine colour. Pale yellow, like weak lemonade, usually means you're drinking enough. Dark yellow or amber means you need more water right away. Set reminders on your phone if you often forget to drink through the day.

Diet and salt

What you eat plays a big role too. A diet high in salt makes your kidneys push out more calcium into your urine, which raises your risk of calcium stones.

Too much animal protein, like large amounts of red meat, chicken and eggs, can also raise the level of uric acid and calcium in your urine.

Sugary drinks, especially those with high fructose corn syrup, have been linked to a higher risk of stones as well.

A plate of biryani or a few pieces of tandoori chicken now and then is fine. The real risk comes from eating large amounts of meat every day, along with very little water.

Other risk factors

Some things that raise your risk are out of your direct control.

Family history — if a parent or sibling has had stones, your own risk goes up
Being overweight or obese
Certain conditions like gout, inflammatory bowel disease, or repeated urinary infections
Some medicines and supplements, including excess calcium or vitamin C supplements
A gut surgery that changes how your body absorbs calcium and oxalate
Having had a stone before — once you've had one, your risk of another is high⁵

Diabetes and high blood pressure also raise your risk. Both affect how your kidneys handle water and salt. Working long hours in a hot kitchen or a non-air-conditioned office can cause heavy sweating too. That counts as fluid loss, even without exercise.

Men tend to get kidney stones more often than women, though the gap has been narrowing in recent years. Stones are most common between the ages of 30 and 50.

What are the different types of stones?

Not all kidney stones are made of the same material. Knowing the type helps your doctor plan the right treatment and prevention plan.

Calcium oxalate

This is the most common type by far. It forms when calcium in your urine combines with oxalate, the substance found in spinach, beetroot, nuts and chocolate².

Most people with this type of stone don't have too much calcium in their blood. The problem is usually about how much calcium and oxalate end up in the urine, and how concentrated that urine is.

These stones often look yellow or brown and feel rough, almost like a bit of gravel. Some are smooth and round instead. The shape alone doesn't tell your doctor much, so lab testing still matters.

Uric acid

Uric acid stones form when your urine is too acidic for long periods. This is often linked to diets heavy in red meat, seafood and alcohol, and is more common in people with gout or diabetes.

These stones can sometimes be dissolved with medicine that makes the urine less acidic, without needing surgery, if caught early.

People who eat a lot of non-vegetarian food, drink beer often, or have high uric acid from gout are more likely to form this type. The good news is these stones often respond well to diet changes and urine-alkalising medicine.

Struvite and cystine

Struvite stones form after certain urinary infections. They can grow fast and become quite large, sometimes filling a large part of the kidney. Treating the underlying infection is a key part of managing these.

Cystine stones are rare. They run in families and happen because of a genetic condition where the kidneys leak too much of an amino acid called cystine into the urine². People with this condition usually need lifelong monitoring by a urologist.

Struvite stones are sometimes called infection stones for this reason. Women get them more often than men, since urinary infections are more common in women. If infections keep coming back, ask your doctor to check for a hidden stone.

Which foods should you avoid with kidney stones?

If you've had a calcium oxalate stone, which most people have, diet changes can lower your risk of another one. The keyword here is balance, not banning entire food groups.

High-oxalate foods

Cutting back on high-oxalate foods can help³. This doesn't mean cutting them out completely, since many are otherwise healthy. It means eating them in smaller amounts and not every single day.

Foods higher in oxalate include

Spinach and other leafy greens like beet greens
Beetroot
Nuts, especially almonds and cashews
Chocolate and cocoa
Sweet potatoes
Bran and wheat germ
Okra (bhindi) and brinjal in larger amounts

A useful trick is to pair these foods with a calcium source in the same meal, such as a glass of milk or a bowl of curd. Calcium and oxalate bind together in your gut before they even reach your kidneys, so less oxalate ends up in your urine.

Here's a simple lunch example. If you're having spinach dal, add a glass of buttermilk or a small bowl of curd alongside it. This one habit lowers how much oxalate reaches your kidneys.

Salt and sugary drinks

High salt intake is one of the biggest dietary drivers of calcium stones. Packaged snacks, papad, pickles, instant noodles and restaurant food are often loaded with salt without you realising it.

Try to keep added salt to about one small teaspoon a day across all your meals. Read labels on packaged food, since sodium hides in bread, sauces and namkeen too.

Sugary sodas and packaged fruit juices are worth cutting down as well. Plain water, buttermilk (chaas) and fresh lime water without added sugar are better everyday choices.

Watch out for foods that don't taste salty but still carry a lot of sodium. Bread, cornflakes, sauces and even sweet biscuits often hide salt. Cooking at home with fresh ingredients gives you the most control.

Getting the calcium balance right

Here's something that surprises a lot of people. Low-calcium diets can actually raise your risk of stones, not lower it.

When you don't eat enough calcium, your gut has less calcium available to bind with oxalate. More oxalate then gets absorbed into your blood and passed out through your kidneys.

So unless your doctor has told you otherwise, don't stop eating dairy or other calcium-rich foods. The goal is a normal amount of calcium from food, paired with lower oxalate and lower salt, not calcium restriction.

Calcium supplements are a different story. High-dose calcium supplements taken without food have been linked to higher stone risk, so check with your doctor before starting any supplement.

Here's a simple example. Two cups of milk a day, plus normal amounts of curd, paneer or cheese in your meals, is usually a healthy target. Ask your doctor if you're unsure what's right for you.

How common are kidney stones in India?

Kidney stones are far from rare in India. A study on kidney stone disease found that around 12% of the Indian population is prone to urinary stones, and that figure rises to nearly 15% in North India⁶.

That means roughly one in eight people you know may face a stone at some point. Kidney stones are one of the most common reasons people visit a urologist at Indian hospitals.

The stone belt

Certain parts of the country, often called the "stone belt," see especially high rates of kidney stones. This includes large parts of North and Northwest India, where hot summers and hard water are common.

Hard water contains higher levels of minerals like calcium and magnesium. While hard water alone isn't proven to directly cause stones, it's one of several regional factors doctors point to alongside diet and climate.

States like Rajasthan, Gujarat, Punjab, Haryana and parts of Madhya Pradesh often report higher stone rates. Doctors in these regions remind patients to drink more water during summer, when the risk climbs fastest.

Heat and dehydration

India's long, hot summers are a major reason stones are so common here. People who work outdoors, in fields, construction sites or on the road, lose a lot of fluid through sweat and often don't replace it with enough water during the day.

Factory and outdoor workers, delivery riders, farmers and anyone who spends hours in the heat with limited access to clean drinking water face a higher risk. Simple habits, like carrying a water bottle and taking regular water breaks, make a real difference here.

If you work outdoors, try to drink a glass of water every hour, even if you don't feel thirsty. Thirst is often a late sign that your body is already low on fluid. A pinch of salt and sugar in water can also help on very hot days.

How are kidney stones diagnosed?

If you go to a doctor with symptoms of a possible stone, they'll usually start by asking about your pain, your urine changes, and your medical history.

Try to describe your pain as clearly as you can. Say where it started, how it moved, and how strong it feels on a scale of one to ten. This helps your doctor decide how urgent your case is.

Scans and urine tests

A CT scan (a detailed X-ray that builds a 3D picture) without contrast dye is the most accurate way to find a kidney stone and check its exact size and location. It's quick and widely available at diagnostic centres across India.

An ultrasound is often used first, especially in pregnant women or when doctors want to avoid radiation. It's cheaper and doesn't use X-rays, though it can miss very small stones.

A urine test checks for blood, signs of infection, and crystals. Your doctor may also ask for a 24-hour urine collection, where you collect all your urine over a full day, to measure exactly how much calcium, oxalate, salt and other minerals your body is passing out.

Blood tests check your kidney function and levels of calcium, uric acid and other minerals.

A CT scan usually takes less than five minutes and doesn't hurt. You lie still on a table while the machine takes pictures. No injection is needed for a plain stone-check scan.

Testing the stone itself

If you manage to pass a stone, or if one is removed during a procedure, your doctor will usually send it to a lab to find out exactly what it's made of.

Knowing the stone's makeup, whether it's calcium oxalate, uric acid, struvite or cystine, changes the prevention plan your doctor gives you afterward. This one test can save you from repeating the same painful mistake a second time.

If you're passing a stone at home, straining your urine through a clean cloth or a tea strainer helps catch it. Bring the stone to your doctor in a clean, dry container, even if it looks tiny.

How are kidney stones treated?

Treatment depends mainly on the size of the stone, where it is, and how much trouble it's causing⁴. A tiny stone in the kidney needs a very different plan than a large stone stuck in the ureter.

Small stones you can pass

Stones smaller than about 4-5mm often pass on their own within a few weeks. Your doctor may suggest pain relief, plenty of fluids, and sometimes a medicine called an alpha-blocker that relaxes the ureter to help the stone move down more easily.

During this waiting period, you'll usually be asked to urinate through a strainer or a fine cloth so the stone can be caught and sent for testing once it passes.

Mild to moderate pain is normal during this time. Sudden, severe pain or fever means you should go back to the doctor right away, even before your follow-up date.

Shock wave lithotripsy

Shock wave lithotripsy, or SWL, uses focused sound waves from outside your body to break a stone into smaller pieces⁴. The tiny fragments then pass out in your urine over the following days.

It's done without cuts or surgery, usually as a day procedure, and works best for stones up to about 1.5 to 2cm depending on their location. You might feel some ache afterward, and it can take a couple of sessions for larger stones.

You're usually awake or lightly sedated during the procedure. Most people go home the same day and return to light activity within a day or two. A follow-up scan checks whether the pieces have cleared.

Ureteroscopy and surgery

Ureteroscopy involves passing a thin, flexible scope up through your urethra and bladder to reach the stone directly, then breaking it with a laser and removing the pieces. There are no external cuts, and most people go home the same day or the next morning.

For larger stones, especially ones over 2cm or stuck deep in the kidney, doctors often use a procedure called percutaneous nephrolithotomy or PCNL. This involves a small cut in your back to reach the kidney directly and remove the stone. It usually needs a short hospital stay of one to three days.

After ureteroscopy, your doctor may place a small tube called a stent inside your ureter for a week or two. This keeps the ureter open while it heals. Mild discomfort or a frequent urge to urinate is normal with a stent in place.

Recovery from PCNL takes a bit longer than the other options. Most people feel back to normal within two to three weeks. Your doctor will schedule a scan afterward to confirm no fragments remain.

The table below gives a rough sense of how these options compare, though your urologist will always decide based on your specific scan.

Treatment	Best for	Cuts needed	Typical recovery	Rough cost in India
Watchful waiting + fluids	Stones under 5mm	None	1-3 weeks	Consultation only
Shock wave lithotripsy (SWL)	Stones up to ~1.5-2cm	None	2-3 days	₹10,000-25,000
Ureteroscopy (URS)	Stones in the ureter or kidney, most sizes	None (scope through natural passage)	2-5 days	₹40,000-90,000
PCNL	Large stones, over ~2cm	One small cut in the back	1-2 weeks	₹70,000-1,50,000

Costs vary a lot depending on the city, the hospital, and whether you use insurance, a government scheme, or pay out of pocket. Always ask for a written estimate before any procedure.

How to prevent kidney stones coming back

Once you've had a kidney stone, your risk of getting another one is high, so prevention matters as much as treatment⁵.

Water first

This is the single most powerful thing you can do. Aim to drink enough water that your urine looks pale yellow, almost like light lemonade, not dark yellow.

Spread your water intake through the day rather than gulping it all at once. Keep a bottle with you at work, in the car, or by your bed, and sip through the day, especially during hot months.

If you sweat heavily from exercise, physical work, or the weather, drink more than the usual 2.5 to 3 litres to make up for what you lose.

Try keeping a marked bottle, one that shows how many litres you've had so far. Some people find it easier to drink from a large bottle refilled twice a day than to track small glasses one by one.

Everyday diet changes

Small, steady habits work better than dramatic short-term diets.

Cut back on added salt in cooking and packaged snacks
Keep eating normal amounts of calcium-rich food like milk, curd and paneer, spread across meals
Go easy on high-oxalate foods like spinach, beetroot and nuts, and pair them with a calcium source when you do eat them
Limit red meat and very large portions of protein at one sitting
Cut down on sugary sodas and packaged juices
Ask your doctor before starting calcium, vitamin C, or vitamin D supplements

Small changes stack up over months. Swapping one sugary drink a day for water, or choosing home-cooked food over packaged snacks twice a week, adds up to a real drop in risk over a year.

If your lab tests show a specific type of stone, your urologist may give you a more targeted diet plan, sometimes with the help of a dietitian. This is especially useful if you've had more than one stone.

When should you see a doctor?

Some kidney stone symptoms need urgent medical care, not a wait-and-see approach.

Get medical help right away if you have

Severe pain that isn't easing with regular painkillers
Fever or chills along with back or side pain
Nausea and vomiting that won't stop
Difficulty passing urine at all
Visible blood in your urine
Pain in only one kidney along with confusion or a very fast heartbeat
Pain so bad you can't stand up straight or walk
A history of only one working kidney, along with new stone symptoms

A fever with stone symptoms can mean the urine is infected behind a blocked stone. This combination can turn serious quickly and usually needs same-day treatment, sometimes with a hospital admission.

Even without these red flags, it's worth seeing a urologist if you notice repeated urine infections, ongoing lower back discomfort, or you've had a stone before and want a prevention plan. Catching a stone early, while it's still small, almost always means a simpler, cheaper and less painful treatment than waiting until it grows.

Keep a simple note on your phone with your past stone history, including the type of stone if you know it, and any medicines you take. This saves time if you ever need emergency care.

Worried about your symptoms? You can consult a urologist on SpotMedics — compare urologists, read what each doctor treats, and book an appointment free in about a minute.