Kidney Stones (Passing) - Causes, Treatment & When to See a Doctor

What is Kidney Stones (Passing)?

Kidney stones are hard deposits made of minerals and salts that form inside the kidneys. When these stones move through the urinary tract, they can cause severe pain and discomfort as they pass from the kidney to the bladder or out of the body. Passing a kidney stone is a common symptom associated with this condition, often indicating a kidney stone issue. While small stones may pass naturally, larger stones may require medical intervention to avoid complications like urinary tract blockages or infections.

It’s important to distinguish between the act of “passing” a stone and having a stone in the kidney. Passing can occur spontaneously, with or without discomfort, depending on the stone’s size and location. CDC notes that while passing stones is typically temporary, it can still signal an underlying issue requiring attention.

Common Causes

Kidney stones form when urine becomes concentrated, allowing minerals to crystallize and clump together. Below are 8-10 conditions or factors linked to their development:

• Dehydration: Not drinking enough fluids increases urine concentration, raising the risk of stones.
• Calcium stones: Most common type, often linked to high calcium intake or oxalate-rich foods.
• Uric acid stones: Associated with high-purine diets (e.g., red meat, shellfish) or conditions causing acidic urine.
• Cystine stones: Rare genetic disorder causing excess cystine in urine.
• Medical conditions: Hyperparathyroidism, renal tubular acidosis, or inflammatory bowel disease.
• Obesity: Excess weight increases stone risk.
• Certain medications: Diuretics, anticonvulsants, or vitamin C supplements in large doses.
• Digestive diseases: Inflammatory bowel disease can alter mineral absorption.
• Dietary factors: High intake of animal protein, sodium, or oxalate-rich foods (e.g., spinach, rhubarb).
• Metabolic disorders: Imbalances in uric acid or calcium excretion.

NIH Kidney Disease (NIDDK) emphasizes that identifying the root cause is critical for effective prevention and treatment.

Associated Symptoms

Passing a kidney stone is often accompanied by other symptoms, which vary based on the stone’s size and location. Common associated symptoms include:

• Severe flank pain: Sharp or cramping pain in the lower back or side, often radiating to the abdomen or groin.
• Hematuria: Blood in the urine, changing its color to pink, red, or brown.
• Frequent urination: Increased urge to urinate, sometimes with small amounts of discomfort.
• Nausea or vomiting: Caused by the body’s response to pain or stone movement.
• Cloudy or foul-smelling urine: Indicative of infection, which can complicate stone passing.
• Fever or chills: Suggest a urinary tract infection (UTI) complicating the stone passage.
• Painful urination: As the stone exits the urethra, burning or stinging may occur.
• Fatigue: Severe pain or fever can lead to exhaustion.

While some symptoms resolve once the stone passes, others may require medical evaluation to rule out infections or blockages (Cleveland Clinic).

When to See a Doctor

Most kidney stones pass spontaneously within 1-2 weeks, but certain signs warrant immediate medical attention:

• Persistent, severe pain that doesn’t ease with home care.
• Blood in the urine accompanied by fever or chills.
• Inability to urinate due to a blocked stone.
• Pain so intense it interferes with daily activities.
• History of recurrent stones or large stone sizes.

Mayo Clinic advises consulting a healthcare provider if pain lasts more than 3-4 hours or if symptoms suggest infection (e.g., fever). Early intervention can prevent complications like kidney damage.

Diagnosis

To diagnose kidney stones and determine their type, healthcare providers may use the following methods:

1. Medical history and physical exam: Questions about symptom duration, diet, and family history of stones.
2. Imaging tests:
   • CT urogram: Gold standard for detecting stone size and location.
   • Ultrasound: Often used for pregnant individuals to avoid radiation.
   • 24-hour urine test: Measures stone-forming substances in urine.
3. Urine analysis: Checks for crystals, infection, or other abnormalities.
4. Blood tests: Evaluates calcium, uric acid, or urate levels.

WHO notes that accurate diagnosis ensures appropriate treatment, especially for recurrent cases.

Treatment Options

Treatment depends on the stone’s size, location, and symptoms. Options include:

Medical Interventions

• Shock wave lithotripsy: Uses sound waves to break stones into smaller pieces.
• Ureteroscopy: A scope is inserted to remove or fragment stones.
• Percutaneous nephrolithotomy: For large stones, a scope removes them via small incisions.
• Dissolving agents: For uric acid stones, allopurinol or potassium citrate may be prescribed.

Home Care

• Hydration: Drink 2-3 liters of water daily to help pass stones.
• Pain management: Over-the-counter NSAIDs (e.g., ibuprofen) or prescribed opioids for severe pain.
• Alpha-blockers: Medications like tamsulosin relax urinary tract muscles to aid stone passage.
• Dietary adjustments: Reduce sodium, oxalate, or animal protein intake as advised by a doctor.

MedicineNet highlights that gradual passage with hydration is often successful for stones under 5mm.

Prevention Tips

Preventing kidney stones involves lifestyle and dietary changes. Consider these strategies:

• Stay hydrated: Aim for 2-3 liters of urine output daily.
• Balance diet: Limit oxalate-rich foods (e.g., spinach, nuts) and animal protein.
• Monitor calcium intake: Avoid excess supplements; consume dairy in moderation.
• Reduce sodium: Cut processed foods and salt intake.
• Exercise regularly: Helps maintain a healthy weight and metabolism.
• Avoid fad diets: Rapid weight loss or very low-fluid diets increase risk.
• Regular check-ups: Especially if prone to stones, to monitor urine composition.

Kidney.org emphasizes that consistent hydration is the cornerstone of prevention.

Emergency Warning Signs