Kidney Stones

Kidney stones are hard deposits made of minerals and salts that form inside the kidneys. They can vary in size from a grain of sand to a golf ball. When a stone moves into the ureter (the tube connecting the kidney and bladder), it can block the flow of urine and cause sudden, intense pain. The most common types of stones contain calcium, but uric acid, struvite, and cystine stones also occur.

Many stones pass on their own within a few days or weeks. Larger stones may require medication, procedures to break them apart, or surgery. Staying hydrated and understanding risk factors can help prevent future stones.

Symptoms often start suddenly when a stone begins to move:

• Severe flank pain: Sharp pain in the back, side, or lower abdomen that may move toward the groin
• Painful urination: Burning or discomfort when urinating
• Blood in urine: Pink, red, or brown urine
• Frequent urination: Feeling the need to urinate more often
• Cloudy or foul-smelling urine
• Nausea and vomiting
• Restlessness: Difficulty finding a comfortable position

Call emergency services if you experience:

• Fever or chills with flank pain (possible infection)
• Inability to urinate
• Pain that is sudden, severe, and unrelenting
• One kidney or a history of kidney transplant and sudden pain

Kidney stones form when urine contains more crystal-forming substances than the fluid can dilute. Risk factors include:

1. Dehydration: Not drinking enough fluids concentrates urine
2. Diet: High intake of sodium, oxalate-rich foods (spinach, nuts), or animal protein
3. Medical conditions: Hyperparathyroidism, gout, inflammatory bowel disease
4. Family or personal history: Previous stones increase risk
5. Medications and supplements: Certain diuretics, calcium-based antacids, high-dose vitamin C
6. Obesity or metabolic syndrome

To lower the risk of stones or help pass a small stone:

1. Hydration:
   • Drink enough fluids to produce clear or light-yellow urine
   • Aim for 2–3 liters of water daily unless your doctor advises otherwise
   • Add citrus (lemon or lime) to water to increase citrate intake
2. Pain Management:
   • Over-the-counter pain relievers (ibuprofen, naproxen) if approved by your doctor
   • Use heating pads to ease flank discomfort
3. Dietary Adjustments:
   • Reduce sodium (less than 2,300 mg/day)
   • Moderate animal protein intake
   • Limit high-oxalate foods if you form calcium oxalate stones
   • Ensure adequate dietary calcium from food (not excessive supplements)
4. Monitor Urine:
   • Strain urine to catch the stone for analysis
   • Track stone passage and symptoms
5. Stay Active:
   • Light walking may help a stone move

• Persistent flank pain that does not improve with medication
• Blood in urine lasting longer than a day
• Difficulty urinating or reduced urine output
• Recurrent stones or family history
• Chronic health conditions (kidney disease, diabetes)

• Stones larger than 5–6 mm
• Stones that do not pass after several weeks
• Frequent recurrences needing metabolic evaluation
• Consideration of procedures such as shock wave lithotripsy, ureteroscopy, or percutaneous nephrolithotomy

Evaluation may include:

1. Urinalysis: Checks for blood, infection, or crystal-forming substances
2. Blood Tests: Assess kidney function, calcium, uric acid levels
3. Imaging:
   • Non-contrast CT scan (most accurate)
   • Ultrasound (preferred during pregnancy)
   • X-ray (KUB) for certain stone types
4. Stone Analysis: Laboratory testing of passed stones determines composition

• Watchful Waiting: Hydration and pain control for small stones likely to pass
• Medications:
  • Alpha blockers (tamsulosin) to relax ureter muscles
  • Medications to prevent specific stone types (thiazide diuretics, allopurinol, potassium citrate)
• Procedures:
  • Shock wave lithotripsy to break stones into smaller pieces
  • Ureteroscopy with laser to remove or fragment stones
  • Percutaneous nephrolithotomy for large or complex stones

• Drink enough fluids to produce at least 2 liters of urine daily
• Limit sodium and moderate animal protein
• Maintain healthy weight and activity level
• Follow individualized dietary advice based on stone type
• Attend follow-up appointments and repeat imaging as recommended

Most kidney stones pass without permanent damage. With proper hydration, diet changes, and medical follow-up, many people can reduce the risk of forming new stones and maintain kidney health.