Overview
Kidney stones are hard deposits formed in the kidneys when minerals and salts in the urine accumulate and crystallize. Our country is a high-risk area for stone disease; prevalence reaches 14% of the population.
Small stones may pass through urine without symptoms; however, larger or obstructing stones cause severe pain and complications.
Symptoms
If the stone is not moving, no symptoms occur. When it moves through the urinary tract:
- Severe flank and back pain (renal colic)
- Pain radiating to the groin or lower abdomen
- Wave-like, colicky pain
- Pain, burning when urinating
- Pink, red, or brown urine (bloody)
- Cloudy or foul-smelling urine
- Persistent urge to urinate
- Passing small amounts of urine
- Nausea, vomiting
- Fever, chills (if infection occurs)
Renal colic is one of the most severe pains; often compared to childbirth.
Types of Stones
- Calcium oxalate stones (80%, most common)
- Calcium phosphate stones
- Uric acid stones (in gout patients)
- Struvite stones (infection-related, more common in women)
- Cystine stones (rare, genetic)
Causes
Increased concentration of stone-forming substances in urine (calcium, oxalate, uric acid) or decreased substances that inhibit stone formation.
Risk Factors
Lifestyle and nutrition:
- Insufficient water intake (most important)
- Excessive salt intake
- Excess protein (red meat) intake
- Sugary drinks
- Excessive oxalate-containing foods (spinach, chocolate, nuts)
- Excessive vitamin C supplements
- Obesity
Medical conditions:
- Previous history of stones
- Family history
- Hypercalciuria
- Hyperparathyroidism
- Gout
- Renal tubular acidosis
- Intestinal diseases (Crohn's, malabsorption)
- Recurrent urinary tract infections
- Some medications (diuretics, antacids)
- Bariatric surgery
Demographic:
- Being male (2-3 times more common)
- 30-50 years old
- Living in hot climates
- Sedentary lifestyle
Complications
- Urinary tract obstruction
- Severe infection (urosepsis)
- Kidney damage, kidney failure
- Frequently recurring stones (50% in 10 years)
- Hydronephrosis (kidney swelling)
When to See a Doctor
Emergency:
- Unbearable flank pain
- Bloody urine
- Fever, chills + urinary symptoms
- Persistent vomiting
- Stone symptoms in those with a single kidney
Scheduled visit:
- Recurring stones
- Family history
- Asymptomatic screening request in risk groups
Diagnosis and Treatment
Diagnosis:
- Urinalysis (blood, crystals, infection)
- Non-contrast CT (gold standard)
- Ultrasound (especially in pregnant women, children)
- Plain abdominal X-ray
- Blood tests: creatinine, calcium, uric acid, phosphorus
- 24-hour urine analysis (in recurrent cases)
- Stone analysis (passed stone is examined)
Treatment (according to stone size and location):
Small stones (under 5 mm):
- Plenty of fluid intake (2.5-3 L per day)
- Pain relievers (NSAIDs)
- Tamsulosin (eases stone passage)
- Wait and follow-up
- 90% pass spontaneously within 4-6 weeks
Large stones or with complications:
- ESWL (Extracorporeal shock wave lithotripsy): Concentrated sound waves on the stone
- Ureteroscopy: Endoscopic stone removal or laser fragmentation from inside
- Percutaneous nephrolithotomy (PCNL): Removal of large stones through a small back incision
- Surgery: Open surgery is rarely needed
If infection is present:
- Antibiotic
- Urgent drainage (ureteral stent, percutaneous nephrostomy)
Prevention
The most effective protection: Drink plenty of fluids
- Drink at least 2.5-3 liters of water per day
- Your urine should be light yellow
- More in hot weather, when sweating
Nutrition:
- Reduce salt (below 5 g per day)
- Limit red meat consumption
- Avoid sugary drinks
- Drink lemon juice (contains citrate, inhibits stone formation)
- Get adequate calcium (paradox: restriction increases oxalate stone risk)
- Avoid excessive oxalate (spinach, tea, chocolate, nuts)
- Adequate vegetables and fruits
- Do not overdo vitamin C supplements
Specific recommendations by stone type:
- Uric acid stone: limit meat, fish, shellfish; allopurinol
- Calcium oxalate: limit oxalate, take citrate
- Struvite: treat urinary tract infections
Other recommendations:
- Maintain a healthy weight
- Regular exercise
- If in risk group, annual urinalysis
- Screening if family history exists