Kidney Stone Pain: Symptoms, Causes, and Relief Options

People who've had kidney stones describe it as the worst pain of their lives - worse than childbirth, worse than broken bones. It's an intense, excruciating pain that comes in waves and makes you unable to find a comfortable position.

About 11% of men and 9% of women in the U.S. will experience kidney stones at least once. And if you've had one, there's a 75% chance you'll get another within a few years. But here's the good news: most stones pass on their own, and there are proven ways to prevent them.

Let's talk about what kidney stone pain feels like, what causes these painful crystals, and how to get relief.

What It Feels Like

Kidney stone pain is distinctive and intense:

Location: Flank pain - severe pain in your back or side, between your ribs and hip. Usually one-sided (whichever kidney has the stone).

Pain that radiates: As the stone moves from kidney toward bladder, pain travels:

• From back/side → lower abdomen → groin
• May radiate to testicles (men) or labia (women)

Quality of pain: Sharp, cramping, or waves of intense pain that come and go. Often described as stabbing or knife-like. The pain comes in waves (called renal colic) as your ureter spasms trying to push the stone out.

Can't get comfortable: Unlike muscle pain that eases with certain positions, kidney stone pain persists no matter how you sit, stand, or lie down. You might find yourself pacing or constantly shifting positions trying to find relief.

Associated symptoms:

• Nausea and vomiting (very common with severe pain)
• Blood in urine (pink, red, or brown) - from stone scraping the urinary tract
• Frequent urination or urgent need to pee
• Burning sensation during urination
• Cloudy or foul-smelling urine
• Fever and chills (if infection present - this is serious)

Small vs. large stones: Small stones (under 4mm) may cause no symptoms and pass unnoticed. You might pee them out and never know. Larger stones cause the severe pain.

Duration: Pain can last 20 minutes to an hour per wave, with breaks in between. The whole ordeal (until stone passes) can take days to weeks.

What Causes Kidney Stones

Kidney stones form when certain chemicals in urine become concentrated enough to crystallize and stick together.

Types of Stones

Calcium oxalate stones (most common - 80%): Form when calcium combines with oxalate. Related to diet high in oxalates (spinach, nuts, chocolate) or not drinking enough water.

Calcium phosphate stones: Less common. Associated with certain metabolic conditions or medications.

Uric acid stones: Form when urine is too acidic. More common in people who eat high-protein diets, have gout, or are undergoing chemotherapy.

Struvite stones: Caused by urinary tract infections. Can grow large quickly ("staghorn calculi").

Cystine stones (rare): Caused by genetic disorder where kidneys excrete too much cystine.

Risk Factors

Dehydration (biggest factor): Not drinking enough water concentrates urine, allowing minerals to crystallize. Hot climates and summer months increase stone risk.

Diet:

• High sodium intake
• Excessive animal protein
• High oxalate foods (spinach, rhubarb, nuts, chocolate, tea)
• Low calcium diet (counterintuitively, dietary calcium actually helps prevent stones)

Family history: If relatives have had stones, you're more likely to get them.

Obesity: Higher BMI increases stone risk.

Medical conditions:

• Gout
• Hyperparathyroidism
• Inflammatory bowel disease (Crohn's, ulcerative colitis)
• Chronic diarrhea
• Renal tubular acidosis

Medications:

• Calcium-based antacids
• Some diuretics
• Topiramate (seizure/migraine med)

Previous kidney stones: If you've had one, you're at high risk for more.

When to See a Doctor

Go to the ER or urgent care immediately if:

• Severe pain that you can't manage at home
• Pain with fever and chills (suggests infection - can be life-threatening)
• Blood in urine with severe pain
• Difficulty urinating or complete inability to pee
• Nausea/vomiting so severe you can't keep fluids down

See your doctor soon (not ER) if:

• Mild flank pain
• Blood in urine without severe pain
• History of stones and think you might have another
• Want to discuss prevention after having a stone

Diagnosis

CT scan (most definitive): Non-contrast CT scan shows stone location, size, and number. Gold standard for diagnosis.

Ultrasound: Non-radiation option (good for pregnant women). Less detailed than CT but can identify larger stones and obstruction.

X-ray (KUB): Kidney, ureter, bladder X-ray. Only shows calcium-containing stones (misses uric acid stones).

Urinalysis: Checks for blood, signs of infection, and urine pH.

Blood tests: Check kidney function and levels of stone-forming substances (calcium, uric acid, etc.).

Treatment

Treatment depends on stone size and severity of symptoms:

For Small Stones (Under 5-6mm)

Watchful waiting with medical expulsion therapy: About 90% of stones under 4mm pass on their own within 4-6 weeks. Your doctor will recommend:

hydration: Drink 2-3 liters of water daily to help flush the stone. The more you pee, the better chance of passing it.

Pain management:

• NSAIDs (ibuprofen, naproxen, ketorolac) work better than opioids for kidney stone pain
• Over-the-counter pain relievers for mild pain
• Prescription pain medication for severe pain
• Anti-nausea medication if needed

Alpha blockers: Tamsulosin (Flomax) relaxes the ureter muscles, making it easier for stones to pass. Can reduce time to stone passage by about 30%.

Strain urine: Pee through a strainer to catch the stone when it passes. Your doctor will want to analyze it to determine type and guide prevention.

For Larger Stones or Complications

Extracorporeal shock wave lithotripsy (ESWL): Non-invasive procedure using high-energy sound waves to break stone into smaller pieces you can pass. Most common treatment for stones 5-20mm.

Ureteroscopy: Doctor inserts thin scope through urethra and bladder to reach stone. Uses laser to break it up. Pieces are removed or pass naturally. Good for stones in ureter or lower kidney.

Percutaneous nephrolithotomy: For very large stones (over 20mm) or staghorn calculi. Surgeon makes small incision in back and removes stone directly. Requires hospitalization.

Open surgery: Rarely needed anymore (less than 1% of cases) due to effectiveness of minimally invasive options.

Prevention

Here's the crucial part - kidney stones are preventable!

Hydration (most important): Drink enough water to produce at least 2-2.5 liters of urine daily. Clear or pale yellow urine is the goal. This is the single most effective prevention strategy.

Dietary changes based on stone type:

For calcium oxalate stones:

• Don't restrict calcium (actually helps prevent stones)
• Limit oxalate-rich foods: spinach, rhubarb, nuts, chocolate
• Reduce sodium to under 2,300mg daily
• Limit animal protein to 4-6 ounces daily

For uric acid stones:

• Limit animal protein (meat, fish, poultry)
• Reduce purine-rich foods: organ meats, shellfish, beer
• Alkalinize urine (your doctor may prescribe potassium citrate)

General dietary advice:

• Eat more fruits and vegetables
• Choose whole grains
• Avoid excessive vitamin C supplements
• Limit sugary drinks and foods

Medications for recurrent stones: If dietary changes aren't enough:

• Thiazide diuretics (for calcium stones)
• Potassium citrate (alkalinizes urine)
• Allopurinol (for uric acid stones)

Stay active: Regular exercise helps prevent stones.

Maintain healthy weight: Obesity increases stone risk.

Living with Recurrent Stones

If you're dealing with frequent stones:

Work with a urologist: They can do metabolic workup (24-hour urine collection) to identify exactly why you're forming stones and create personalized prevention plan.

Know your stone type: Always try to catch stones to have them analyzed. Treatment and prevention differ by type.

Stay vigilant: Once you've had stones, you need to be proactive about prevention. Don't get complacent.

The Bottom Line

Kidney stone pain is excruciating, but most stones under 5mm pass on their own with pain management and hydration. Larger stones may need procedures, but minimally invasive options work well.

The key is prevention - especially hydration. Drink enough water to keep urine pale yellow. If you've had stones, work with a urologist to understand your stone type and create a prevention plan.

Don't ignore severe flank pain, especially with fever or inability to urinate. These need emergency evaluation. And remember - if you've passed a stone once, you're at high risk for more unless you take preventive steps seriously.

References

1. National Kidney Foundation - Kidney Stones information
2. Cleveland Clinic - Kidney Stones: Causes, Symptoms, Diagnosis & Treatment
3. Mayo Clinic - Kidney stones symptoms, causes, diagnosis and treatment
4. AAFP - Kidney Stones: Treatment and Prevention
5. University of Utah Health - Kidney Stones Guide (2025)
6. NCBI StatPearls - Renal Calculi, Nephrolithiasis