Kidney Stones: Symptoms, Causes, Treatment & ER Care

Kidney stones are hard clusters of crystals that form within the urinary tract ⁸. Many stones leave the body in urine, but moving stones can cause intense pain ⁸. A stone may also block urine, cause bleeding, or occur with an infection ^7,8.

Knowing the warning signs can help you choose the right level of care. This guide covers symptoms, risks, testing, renal colic treatment, and prevention.

Kidney stones can be as small as sand or, rarely, larger than a golf ball ⁸. They may remain in a kidney or travel through a ureter ⁸. A ureter is a tube that carries urine from a kidney to the bladder.

A moving stone can cause renal colic, which means severe pain from a blocked urinary tract. Pain often starts when a stone enters the urine collection system and blocks urine flow. Pressure above the blockage causes much of the severe pain.

Small stones often pass without a procedure ^1,2. Larger stones may require treatment when they cause pain, blockage, or other problems ^1,2.

Kidney stone pain often begins suddenly in the side or back. It may start near the lower ribs and spread toward the front. The pain can become steady, severe, and difficult to tolerate.

Common symptoms may include:

These symptoms do not confirm a kidney stone. Other health problems can cause similar pain and urinary changes ⁹.

Pain may shift as the stone moves down the ureter. It may feel as if it extends from the groin toward the side. Pain may ease when the stone reaches the bladder.

Stone pain can rise and fall in intensity ^7,8. However, some people experience pain that becomes continuous and severe. Pain location and strength can vary with the stone’s size, position, and degree of blockage.

Small kidney stones may cause no pain or other symptoms ⁸. Doctors may find a silent stone during imaging performed for another reason. A stone may also cause dull back pain, stomach symptoms, or isolated blood in urine.

Blood can be visible or found only during a urine test. However, blood is not present in every case of renal colic. Its absence does not exclude a kidney stone.

Seek emergency care now in these situations:

An abdominal aortic aneurysm can resemble stone pain in some older adults ⁹. This condition involves a weak, enlarged area in the body’s main artery.

Fever and chills are not common with an uncomplicated stone. If fever or chills occur, contact a clinician promptly because they can suggest infection. If fever or chills occur with suspected stone pain, seek immediate emergency evaluation at an emergency department or through urgent urologic care; infection with a blocked kidney is a urologic emergency requiring prompt treatment. Cloudy or bad-smelling urine may also occur with a urinary infection.

Repeated vomiting can cause dehydration and may require hospital care ¹. If liquids will not stay down, seek urgent medical assessment. Hospital staff may give fluids through a vein when dehydration develops ¹.

A urinary infection with a kidney stone may require active stone removal. Some people need fluid support, close monitoring, and intensive hospital care.

Antibiotics treat the infection, but they do not remove the blockage. Drainage is critical when infection and trapped urine occur together.

Do not force extra fluids to relieve renal colic. Increased fluid intake does not reduce acute stone pain ⁹. Follow medical guidance about fluids if vomiting or another condition limits intake.

Kidney stones can form when urine contains too little liquid ^3,8. Urine contains minerals, acids, and salts that normally stay dissolved ⁸. Too little fluid allows these materials to collect and form crystals ⁸.

Low urine volume is a major cause of stone formation. Hot weather and heavy activity can increase fluid needs because sweating removes water ¹. Low urinary citrate or very acidic urine can also promote certain stones.

Doctors classify stones by their chemical makeup. The four main groups include:

Calcium stones may involve excess calcium, oxalate, or uric acid in urine. Low citrate or low urine volume may also contribute.

Uric acid stones have links with gout, diabetes, obesity, and metabolic syndrome. Metabolic syndrome includes several problems linked with blood sugar and body weight.

Struvite stones can grow into large, branching stones called staghorn stones ^3,8. Cystine stones often return and may begin during childhood.

Low fluid intake and low urine output are leading risk factors. Other supported risks include:

A clinician can review your health, diet, and medicines for preventable causes.

Doctors ask about pain, urinary symptoms, prior stones, and family history ^7,9. They also review medical conditions, medicines, and possible pregnancy ⁹. An examination may check for tenderness in the back, side, abdomen, or groin.

Urinalysis is a urine test that can find blood or signs of infection ⁹. A urine culture checks for bacteria that may cause an infection ^7,9. Blood tests can help assess kidney function and other health concerns.

Low-dose noncontrast CT is highly accurate for suspected renal colic in adults ^5,9. “Noncontrast” means the scan does not use injected contrast dye. Guidelines recommend urgent CT for many adults with suspected stone pain.

Ultrasound is preferred instead of CT during pregnancy. It avoids the radiation used during CT imaging. Ultrasound is also recommended first for children and young people with suspected renal colic.

Imaging can show stone size, location, blockage, and kidney swelling ⁹. These details help clinicians choose observation, follow-up, or a procedure ^1,9.

Several problems can resemble kidney stone symptoms. Doctors may consider:

Testing matters because these conditions require different care. Learn more about UTI symptoms and treatment.

A trial of passage means waiting for a stone to leave in urine. It may be suitable when pain is controlled and kidney function remains stable. There must also be no signs of urinary infection.

Most stones smaller than 5 millimeters pass without a procedure. About half of stones between 5 and 10 millimeters pass on their own. Smaller stones and stones lower in the ureter have better passage rates.

A clinician may recommend follow-up imaging during conservative treatment ⁹. Imaging can track the stone and check for kidney swelling ⁹. Seek reassessment if pain continues or the stone does not pass.

NSAIDs are often the first choice for acute renal colic when they are safe ^5,9. NSAIDs are pain medicines that also reduce inflammation. They may provide better pain relief and fewer side effects than opioids ⁹.

A clinician may use another pain medicine if NSAIDs are unsafe or ineffective. Anti-nausea medicine may help when nausea or vomiting occurs. Severe or persistent symptoms may require hospital observation or admission.

Alpha blockers relax muscles and may help some ureteral stones pass. Evidence shows benefit for selected stones between 5 and 10 millimeters. These medicines can cause dizziness, tiredness, or low blood pressure.

Antibiotics are used when an infection is present. They do not remove an obstructing stone. An infected blockage requires drainage as well as antibiotic treatment.

Doctors select procedures based on stone size, location, makeup, and complications ^1,2. Common choices include:

Shock wave treatment is less invasive but may require repeat treatment. Ureteroscopy can remove or break stones within the ureter or kidney ^1,2. Percutaneous treatment is generally used for larger kidney stones ^1,2.

Ongoing severe pain may be a reason for prompt stone treatment. Treatment is also needed when a stone is unlikely to pass.

Drinking enough fluid helps keep urine diluted and flush away stone-forming minerals ¹. Fluid needs vary with weather, activity, urine output, and stone type ¹. Ask for an individual goal if kidney failure or another condition limits fluids ¹.

Helpful food changes may include:

Very low dietary calcium may not be the right choice for calcium stones ^3,8. Ask a clinician before making major food or supplement changes.

Try to catch a passed stone if your care team requests it ¹. A laboratory can identify its type and guide prevention ¹.

Follow-up may include imaging, blood tests, and urine testing. A 24-hour urine collection measures urine volume and mineral levels ¹. Results can reveal low urine output or high levels of stone-forming materials ¹.

Prevention medicine depends on the stone type and test results ^1,7. Potassium citrate may treat low citrate or overly acidic urine ^1,7. Thiazide medicines may help when urine contains too much calcium.

Allopurinol may help selected people with excess urinary uric acid. Antibiotics may be used for some infection-related struvite stones ¹. Other inherited or metabolic causes may need specialized treatment.

Kidney stones may remain silent or cause sudden, severe pain. Their effects depend on the stone’s size, location, movement, and blockage.

Many small stones pass with clinician-guided care ^1,2. Testing can confirm the cause and guide safe treatment. Fluids, food changes, stone analysis, and tailored medicines can lower future risk ^1,7.