Kidney Stones: Symptoms, Causes & Treatment

Kidney stones (Nephrolithiasis) are hard deposits of minerals and acid salts that accumulate in the kidneys. They form when urine becomes too concentrated, allowing minerals to crystallize and solidify. Stones may remain asymptomatic in the kidney, but when they travel down the urinary tract toward the bladder, they cause severe acute pain called renal colic.

Kidney stones are very common, especially in hot and arid regions like the Middle East, including Jordan. It is estimated that 1 in 20 people will develop a kidney stone in their lifetime, with men being 3 times more likely to be affected than women. Stones vary in size from tiny sand-like particles to large masses that can fill a significant portion of the kidney. Common stone types include calcium oxalate (75-85%), calcium phosphate (10-15%), uric acid stones (5-10%), and cystine stones (1-2%).

People who have had kidney stones once are at risk of recurrence within 5-10 years without preventive measures. Most small stones (less than 5 mm) pass on their own with time and fluids, but larger stones may require medical intervention.

Symptoms of kidney stones depend on the size and location of the stone. Small stones may cause no symptoms at all, but larger stones that pass through the urinary tract cause sudden and severe symptoms. Men and women experience essentially the same symptoms, although women's symptoms may sometimes be masked by other gynecological conditions.

• Severe flank and back pain: Sudden, intense pain starting in the flank (between the rib and hip bone) that radiates forward to the lower abdomen and inner thigh (referred pain).
• Renal colic: Intermittent waves of severe pain lasting from 30 minutes to several hours.
• Blood in urine (hematuria): May be visible to the naked eye (red or brown) or detected by urinalysis.
• Nausea and vomiting: Very common with severe pain, may prevent adequate fluid intake.
• Burning during urination: Especially as the stone passes toward the bladder and urethra.
• Frequent and urgent urination: Repeated and urgent need to urinate, especially if the stone is near the bladder.
• Fever and chills: May occur if there is an accompanying bacterial infection.
• Cloudy or foul-smelling urine: Sign of bacterial infection.
• General discomfort and exhaustion: Persistent pain may cause overall fatigue and inability to rest.
• Constipation or diarrhea: Gastrointestinal upset may occur due to pain and nausea.

• Dehydration and insufficient fluid intake: Low water and fluid intake causes urine to become concentrated, increasing mineral crystallization and stone formation.
• Foods high in oxalates: Foods like spinach, peanuts, chocolate, and tea contain oxalates that increase the risk of calcium stone formation.
• Excessive salt and protein consumption: High salt and animal protein intake increase mineral concentration in urine.
• Genetics and family history: Having relatives with kidney stones increases your personal risk.
• Certain chronic diseases: Conditions like gout, hyperparathyroidism, and chronic kidney disease increase stone formation risk.
• Certain medications: Some drugs like diuretics and high-dose vitamins may increase stone risk.
• Prior gastrointestinal surgery: Gastric bypass or reduction surgery increases oxalate absorption.
• Sedentary lifestyle: Physical inactivity and prolonged sitting may increase mineral concentration in urine.

• Male gender: Men are 3-4 times more likely to develop kidney stones than women, especially between ages 20-40.
• Age: Peak incidence occurs between 30-50 years, but stones can occur at any age.
• Obesity and overweight: Elevated BMI is associated with increased stone formation risk.
• Pregnancy and hormones: Some women develop stones during pregnancy due to hormonal changes and dehydration.
• History of previous stones: Those with a prior episode have a 50% risk of recurrence within 10 years.
• High urine acidity: Genetic conditions that increase urine acidity (like gout) increase risk.
• Recurrent urinary tract infections: Repeated kidney and UTIs increase stone formation.
• Thyroid disease and liver disease: These conditions affect mineral and salt metabolism.
• Family history: Having relatives with kidney stones significantly increases personal risk.
• Living in hot and arid climates: Hot climates increase dehydration and urine concentration, especially in Jordan and the Gulf region.

Diagnosis of kidney stones is based on clinical examination, laboratory tests, and medical imaging. The doctor will ask about medical history and symptoms, then perform a physical examination to check for flank tenderness. Confirmation of the stone with imaging is important before starting treatment.

• Urinalysis: Detects blood in urine (hematuria), crystals, and signs of infection. Normal urine should not contain visible blood.
• Blood tests (CBC and chemistry panel): Measures creatinine levels (normal range 0.7-1.3 mg/dL), BUN, calcium, and phosphate. Elevated creatinine may indicate stone obstruction.
• X-ray imaging: Shows dense calcium stones, but may miss less dense stones (uric acid and cystine types).
• Ultrasound: Safe, non-invasive imaging that detects stones and hydronephrosis, but may not be sensitive for small stones.
• Non-contrast Helical CT scan (Low-dose CT KUB): Gold standard for diagnosis (99% sensitivity), detects all stone types and precisely determines size and location with minimal radiation exposure.
• Cystoscopy and ureteroscopy: May be used to visualize and remove small stones, especially in the bladder and urethra.
• 24-hour urine collection: Performed after stone passage or treatment to determine urine composition and identify factors contributing to future stone formation (such as hypercalciuria or hyperuricuria).

Medications

• Analgesics: Ibuprofen 600-800 mg every 6-8 hours or Paracetamol 500-1000 mg help manage pain. For severe pain, your doctor may prescribe stronger pain medications via injection (such as Tramadol or Morphine).
• Anti-nausea drugs: Metoclopramide or Ondansetron relieve nausea and vomiting associated with pain.
• Thiazide diuretics: Hydrochlorothiazide (HCTZ) reduces calcium concentration in urine, used to prevent recurrent stones.
• Allopurinol: Lowers uric acid levels in blood and urine, used to prevent uric acid stones, typical dose 100-300 mg daily.
• Citrate supplements: Potassium citrate prevents stone crystallization, especially useful for preventing recurrent stones.
• Vitamin B6 (Pyridoxine): Reduces oxalate concentration in urine, beneficial for those with hyperoxaluria.

Procedures / Surgery

• Hydration and observation (Conservative management): 80% of small stones (less than 5 mm) pass spontaneously within 2-4 weeks with adequate water intake (2-3 liters daily) and rest. Recommended initially for small uncomplicated stones.
• Extracorporeal Shock Wave Lithotripsy (ESWL): High-energy shock waves directed at the stone to fragment it into smaller pieces that pass easily in urine. Used for stones 2-3 cm in the kidney and ureter. Success rate 60-80%, may require multiple sessions. Minimal discomfort, patient returns to activities within a day.
• Ureteroscopy (URS): Thin tube with camera inserted through urethra and bladder up to the ureter and kidney. Used to directly remove stones or fragment them with laser (Holmium laser) or ultrasound. Very effective (95%+), especially for ureteral and lower pole kidney stones. May require general anesthesia, recovery 1-2 weeks.
• Percutaneous Nephrolithotomy (PCNL): Small incision in the back to directly access the kidney, then stones are removed with specialized instruments. Used for very large stones (over 2 cm) and complex cases. Success rate 90%+, but slightly more complications and longer recovery (2-3 weeks).
• Laser-assisted stone fragmentation: Use of laser (Holmium or Erbium) through the endoscope to precisely fragment stones. Helpful for difficult and hard stones (such as cystine stones).
• Ureteral stent placement: Small tube placed in the ureter to allow urine drainage in cases of complete obstruction or accompanying infection. Removed after 1-2 weeks when obstruction improves.

Lifestyle Changes

• Water and fluid intake: Drink 2-3 liters of water daily (or until urine is pale). This increases urine output and dilutes mineral concentration. In hot regions like Jordan, you may need to drink more.
• Reduce salt: Do not exceed 2,300 mg of salt daily (about one small teaspoon). Excess salt increases urinary calcium.
• Reduce animal protein: Limit meat, chicken, and fish. Recommended intake is 50-100 grams daily. Excess protein increases uric acid and calcium in urine.
• Avoid high-oxalate foods: Reduce spinach, peanuts, chocolate, tea, coffee, and cocoa (especially for those with calcium oxalate stones).
• Adequate calcium: Don't avoid calcium completely! Adequate calcium intake (1000-1200 mg daily from dairy and food sources) helps prevent stone formation. Avoid excess supplements.
• Physical activity: Exercise regularly such as walking or swimming 30 minutes daily. Movement helps stones pass.
• Weight loss: If obese, aim to lose 5-10% of body weight safely.
• Control acidity: Avoid excessive acidity in diet (reduce red meat and alcohol), eat alkaline foods like fruits and vegetables.
• Stay hydrated: Drink enough water throughout the day, especially after exercise and in hot weather.

• Bacterial infection (Pyelonephritis): If a stone completely obstructs the urinary tract, urine cannot drain properly, allowing bacteria to multiply and cause severe kidney infection and potentially life-threatening sepsis if not treated promptly.
• Acute kidney injury: Complete and prolonged ureteral obstruction prevents urine drainage and causes back-pressure in the kidney, damaging kidney cells and causing rapid loss of function.
• Hydronephrosis: Accumulation of urine in the kidney and its enlargement due to obstruction, may cause permanent kidney damage if prolonged.
• Renal scarring and fibrosis: Recurrent infections and obstructions may leave scars in kidney tissue and permanently reduce function.
• Bleeding and tissue necrosis (Hematuria): Large and sharp stones may cause wounds in the urinary tract lining and lead to bleeding and tissue death.
• Ureteral perforation: During stone removal or fragmentation, perforation of the ureteral wall may occur, causing urine leakage into surrounding tissues and potentially requiring emergency surgery.
• Male infertility: Recurrent infections and multiple surgeries may affect the epididymis and seminal vesicles, reducing fertility.
• Recurrent and chronic stones: Those with one stone episode have 50% risk of recurrence, and may develop chronic stone disease requiring repeated treatments and continuous monitoring.

• Drink plenty of water: Aim for 2.5-3 liters of water daily so urine is light-colored (not dark). This dilutes mineral concentration. In Jordan's hot climate, you may need to drink more, especially after exercise.
• Reduce dietary salt: Aim for less than 2,300 mg of salt daily. Reduce canned, frozen, and fast foods.
• Follow a balanced diet: Eat plenty of fruits and vegetables (especially high-potassium ones like bananas and avocados) and whole grains. This reduces urine acidity.
• Eat adequate calcium: 1,000-1,200 mg daily from dairy, cheese, yogurt, and dark leafy vegetables. Adequate calcium prevents oxalates from accumulating.
• Reduce animal protein: Do not eat more than 100 grams of animal protein daily. Reduce red meat, chicken, and fish, choose plant-based proteins sometimes (lentils, chickpeas).
• Avoid alcohol and sugary drinks: Alcohol and high-sugar beverages (especially colas and concentrated juices) increase stone risk.
• Lose weight: If obese, losing 5-10% of body weight reduces stone risk.
• Exercise regularly: Walking, swimming, and cycling for 30-45 minutes most days of the week helps prevent stones.
• Regular medical follow-up: If you've had stones before, see your doctor annually and have urine tests and blood work to monitor mineral and salt levels.
• Ask your doctor about preventive medications: If you have recurrent stones, your doctor may prescribe preventive drugs such as citrate, thiazide diuretics, or allopurinol.