Overview
Kidney stones are hard, pebble-like masses that form when minerals and salts in urine crystallize, most often in the kidneys, and can cause severe pain as they move through the urinary tract.
Disease Summary
- Category
- Non-Communicable Disease
- Cause
- Buildup of minerals such as calcium, oxalate, or uric acid in the urine that crystallize and form hard stones
- Transmission
- Not applicable; kidney stones are not contagious and cannot be spread between people
- Body System
- Urinary System
- Preventable
- Yes
- Curable
- Yes
Symptoms
Common Symptoms
Symptoms often depend on the size of the stone and whether it is moving through the urinary tract.
Severe Flank or Back Pain
Sharp, cramping pain in the side or back, often below the ribs, that may come in waves.
Pain Radiating to the Lower Abdomen or Groin
Pain that shifts location as the stone moves through the urinary tract.
Blood in Urine
Urine may appear pink, red, or brown due to blood from the irritated urinary tract.
Nausea and Vomiting
Often accompanies the severe pain of a kidney stone.
Danger Signs
Seek urgent medical attention if any of the following occur.
Fever and Chills
May indicate an infected kidney stone, which is a medical emergency.
Inability to Urinate
A complete blockage of urine flow needs urgent medical attention.
Unbearable Pain
Pain so severe that you cannot find a comfortable position should be treated as an emergency.
Persistent Vomiting
Ongoing vomiting can lead to dehydration and needs medical evaluation.
Diagnosis
Clinical Assessment
Diagnosis begins with a review of symptoms, medical history, and a physical examination.
Imaging
CT scans or ultrasound can locate a stone and determine its size and position.
Urine and Blood Tests
Help identify the type of stone and check for infection or kidney function problems.
Laboratory Tests
CT Scan of the Abdomen and Pelvis
Provides detailed images to precisely locate and measure kidney stones.
Abdominal Ultrasound
Can detect kidney stones without radiation exposure, often used in pregnant women and children.
Urinalysis
Checks for blood, crystals, and signs of infection in the urine.
Stone Analysis
Identifies the type of stone, which helps guide prevention strategies.
Treatment
Pain Management and Hydration
Increased fluid intake and pain medication help many smaller stones pass on their own.
Stone Removal Procedures
Larger stones or those causing a blockage may need shock wave lithotripsy or surgical removal.
Prevention
Drink plenty of fluids
Staying well hydrated helps dilute urine and flush out minerals that can form stones.
Reduce salt intake
Lowering sodium intake can reduce the amount of calcium excreted in urine.
Limit foods high in oxalate
Reducing intake of foods such as spinach and nuts can help prevent certain types of stones.
Maintain a healthy weight
Obesity is linked to a higher risk of kidney stones, so maintaining a healthy weight can help lower risk.
Risk Factors
High Risk
These factors substantially increase the likelihood of developing kidney stones.
- Previous kidney stones
- Family history of kidney stones
- Dehydration or low fluid intake
Increased Risk
These factors are associated with a moderately higher risk of kidney stones.
- Diets high in salt, sugar, or animal protein
- Obesity
- Certain digestive diseases affecting mineral absorption
Additional Contributing Factors
Other factors linked with an increased likelihood of kidney stones.
- Certain medications, including some diuretics
- Prolonged immobility
- Family or personal history of urinary tract infections
Complications
Urinary Tract Infection
A blocked kidney stone can lead to infection in the urinary tract.
Kidney Damage
Recurrent or untreated stones can, over time, contribute to reduced kidney function.
Obstruction
A stone can block the flow of urine, causing swelling and pain in the kidney.
When to Seek Medical Care
Fever with Flank Pain
May indicate an infected kidney stone and needs urgent evaluation.
Unbearable Pain
Severe pain that cannot be controlled at home should be treated as an emergency.
Inability to Urinate
A complete blockage of urine flow requires immediate medical attention.
Persistent Vomiting
Can lead to dehydration and needs medical assessment.
Prognosis
Good for Small Stones
Most small kidney stones pass on their own within a few weeks with adequate fluids and pain control.
Higher Risk of Recurrence
People who have had one kidney stone are at higher risk of developing another.
Excellent with Prompt Treatment
Larger or obstructing stones treated promptly generally have excellent outcomes.
Differential Diagnosis
Appendicitis
Can cause similar abdominal pain, particularly when a stone is on the right side.
Urinary Tract Infection
Can cause pain and blood in urine that may resemble a kidney stone.
Ovarian Cyst or Torsion
Can cause similar flank or lower abdominal pain in women.
Musculoskeletal Back Pain
Muscle strain can sometimes be mistaken for the flank pain caused by a kidney stone.
References
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
NIH guidance on the causes, symptoms, and types of kidney stones.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Treatment
NIH guidance on treating and preventing kidney stones.
National Kidney Foundation
Patient-focused guidance on kidney stone causes, symptoms, and treatment.
Frequently Asked Questions
Can kidney stones cause death?
No. Kidney stones themselves don’t cause death, though untreated complications such as infection can become serious if ignored.
Will I need surgery for a kidney stone?
Not always. Many small stones pass on their own with fluids and pain control, but larger stones may need a procedure.
Can kidney stones come back?
Yes. People who have had one kidney stone are at higher risk of developing another, so prevention strategies are important.
Do I need to change my diet after a kidney stone?
Often yes. Dietary changes depend on the type of stone you had, so knowing the stone type helps tailor an effective prevention plan.