If you suspect you have a kidney stone, the first steps are to stay hydrated, manage your pain, and get a diagnosis confirmed. Most kidney stones smaller than 5 mm will pass on their own, but knowing what you’re dealing with helps you decide whether you can wait it out at home or need medical attention sooner.
Recognizing Kidney Stone Symptoms
The hallmark symptom is intense pain on one side of your body, between your lower ribs and hip. This pain often radiates to your back, groin, or lower abdomen. It can feel like a dull ache that won’t quit, or it can hit in sharp waves lasting 20 to 60 minutes at a time. The pain typically peaks one to two hours after it starts.
Other common signs include pain when you urinate, blood in your urine (which may look pink, red, or brown), cloudy or foul-smelling urine, and urinating more or less frequently than normal. Nausea and vomiting often accompany the pain. Not every stone causes dramatic symptoms. Smaller stones sometimes produce only mild discomfort or a vague ache in your side that comes and goes.
When to Go to the Emergency Room
Most kidney stones don’t require emergency care, but certain situations do. Head to the ER if your pain becomes unbearable and you can’t keep fluids down, if you develop a fever or chills alongside stone symptoms, or if you notice you’ve stopped urinating. A fever combined with a kidney stone can signal an infection in the urinary tract, which can become dangerous quickly. The ER can provide stronger pain relief and imaging to assess the situation.
Getting a Diagnosis
If your symptoms are manageable, call your primary care doctor or a urologist. They’ll likely order a non-contrast CT scan, which is the most accurate imaging tool for detecting kidney stones. It reveals the stone’s size, location, and density, all of which determine your treatment plan. Ultrasound is sometimes used as an alternative, particularly for pregnant patients or when radiation exposure is a concern, but CT remains the gold standard.
Your doctor will also check your urine for blood and signs of infection and run basic blood work to assess kidney function. If this isn’t your first stone, they may order a 24-hour urine collection. This test measures levels of calcium, oxalate, citrate, uric acid, and overall urine volume to pinpoint why your body keeps producing stones. You eat and drink normally during the collection so the results reflect your actual habits.
Managing Pain at Home
Over-the-counter anti-inflammatory medications like ibuprofen or naproxen are your best options for pain relief while waiting for a stone to pass. These reduce both pain and the inflammation caused by the stone irritating your ureter. Acetaminophen can help if you can’t take anti-inflammatories. A heating pad on your side or lower back can also take the edge off between pain waves.
Drink plenty of water. Aim for enough fluid to produce at least 2 to 3 liters of urine per day, which for most people means drinking roughly 3 liters of water throughout the day. This keeps urine flowing and helps push the stone through. Water is the best choice. Avoid excessive caffeine or sugary drinks that can work against you.
Will the Stone Pass on Its Own?
Your stone’s size is the biggest predictor of whether it will pass without intervention. Research published in the American Journal of Roentgenology tracked passage rates by stone size and found clear patterns:
- 1 to 4 mm: About 76 to 87% pass spontaneously
- 5 to 7 mm: About 47 to 72% pass spontaneously
- 8 mm and larger: Only about 25 to 56% pass on their own
Stones 4 mm or smaller have the best odds, and most pass within a few days to a couple of weeks. Stones in the 5 to 7 mm range are a gray area where your doctor might give you time to pass it naturally, sometimes with medication to relax the ureter. Anything approaching 10 mm or larger rarely passes without help. Your doctor may also prescribe a medication that relaxes the smooth muscle in your ureter, making it easier for mid-sized stones to move through.
While waiting, your doctor may ask you to strain your urine through a fine mesh or filter. Catching the stone allows a lab to analyze its composition, which is valuable for preventing future stones.
Procedures for Stones That Won’t Pass
When a stone is too large, too stubborn, or causing complications like infection or kidney damage, three main procedures are available.
Shock wave lithotripsy is the least invasive option. You lie on a table while focused sound waves break the stone into smaller fragments that you then pass naturally. It works best on stones 10 mm or smaller that aren’t located in the lower part of the kidney. Recovery is relatively quick, though you may have soreness and pass gritty fragments for several days afterward.
Ureteroscopy involves a thin, flexible scope passed through your urethra and bladder up into the ureter. The surgeon can either grab small stones with a tiny basket or use a laser to break larger ones apart. This approach tends to have higher success rates than shock wave lithotripsy and is the preferred option if you take blood thinners that can’t be stopped. You’ll typically go home the same day, sometimes with a temporary stent in the ureter to keep it open while it heals.
Percutaneous nephrolithotomy is reserved for large stones, generally bigger than 2 cm. The surgeon makes a small incision in your back and uses a scope to break up and remove the stone directly from the kidney. It’s the most effective approach for large stones but requires general anesthesia and a short hospital stay, usually one to two days.
Preventing the Next Stone
About half of people who get a kidney stone will get another within five to ten years, so prevention matters. The single most important step is staying well hydrated. Aim for up to 3 liters of fluid daily as an ongoing habit, not just during an active stone episode.
The most common type of kidney stone, calcium oxalate, accounts for 56 to 61% of all stones. Despite what you might assume, you should not cut back on calcium. Getting adequate calcium through food actually helps, because calcium binds to oxalate in your digestive tract and prevents it from reaching your kidneys. The key dietary changes for calcium oxalate stones include limiting high-oxalate foods like spinach, rhubarb, nuts, beans, chocolate, and wheat, keeping sodium under 2 grams per day, eating enough fruits and vegetables to keep urine less acidic, keeping vitamin C supplements under 1 gram daily, and avoiding processed and heavily salted foods.
Uric acid stones, which make up 9 to 17% of cases, are strongly linked to high protein intake and alcohol. Reducing animal protein, cutting back on alcohol, and making urine more alkaline through a plant-rich diet are the primary strategies. For people with diabetes, regular coffee and tea consumption may also help.
If you’ve had more than one stone, the 24-hour urine test becomes especially important. It measures how saturated your urine is with the specific crystals that form stones, so your doctor can tailor prevention to your exact chemistry rather than relying on general advice. Some people need prescription medications to change their urine composition, but many can reduce their risk significantly through diet and hydration alone.