Kidney stones, or renal calculi, are hard mineral and salt deposits that form within the kidneys. These stones can develop in any part of the urinary tract, including the kidneys, ureters, bladder, and urethra.
Types of Kidney Stones
Calcium Stones: The most common type, primarily made of calcium oxalate. They can also be composed of calcium phosphate.
Struvite Stones: Form in response to an infection, such as a urinary tract infection (UTI). These stones can grow quickly and become quite large.
Uric Acid Stones: Form in people who don’t drink enough fluids, lose too much fluid, eat a high-protein diet, or have gout.
Cystine Stones: Form in people with a hereditary disorder that causes the kidneys to excrete excessive amounts of certain amino acids (cystinuria).
Causes
Kidney stones form when the urine contains more crystal-forming substances—such as calcium, oxalate, and uric acid—than the fluid in the urine can dilute. At the same time, the urine may lack substances that prevent crystals from sticking together, creating an ideal environment for kidney stones to form.
Symptoms
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- Severe pain in the side and back, below the ribs
- Pain that radiates to the lower abdomen and groin
- Pain that comes in waves and fluctuates in intensity
- Painful urination
- Pink, red, or brown urine
- Cloudy or foul-smelling urine
- Nausea and vomiting
- Persistent need to urinate
- Urinating more often than usual
- Fever and chills if an infection is present
Diagnosis
Imaging: CT scan, X-ray, ultrasound, or intravenous pyelography (IVP) can detect kidney stones.
Blood Testing: To check for excessive calcium or uric acid.
Urine Testing: 24-hour urine collection to measure the volume of urine and mineral levels.
Analysis of Passed Stones: To determine the type of stone and help with future prevention.
Treatment
Small Stones with Minimal Symptoms:
Drinking Water: To flush out the urinary system.
Pain Relievers: Ibuprofen, acetaminophen, or naproxen.
Medical Therapy: Medication to help pass the stone, such as alpha blockers.
Large Stones or Stones Causing Symptoms:
Extracorporeal Shock Wave Lithotripsy (ESWL): Uses sound waves to break the stones into smaller pieces.
Surgery: Percutaneous nephrolithotomy involves removing the stones using small telescopes and instruments inserted through a small incision in the back.
Ureteroscopy: A thin, flexible tube is used to find and remove stones or break them into smaller pieces.
Parathyroid Gland Surgery: If the stones are caused by overactive parathyroid glands, surgical removal of the gland may be necessary.
Prevention
Hydration: Drink plenty of water throughout the day.
Diet: Eat a diet low in salt and animal protein. Reduce foods high in oxalates if you form calcium oxalate stones.
Calcium Intake: Maintain normal dietary calcium, but avoid calcium supplements.
Medications: Your doctor may prescribe medications to prevent certain types of stones.
Kidney stones can be painful and recurrent, but with proper management and preventive measures, their occurrence and impact can be minimized.