(Renal Calculi; Urinary Calculi)
Small, solid particles that form in one or both kidneys and sometimes travel into the ureter (slender muscular tubes that carry urine from the kidneys to the urinary bladder). Stones vary from the size of a grain of sand to a golf ball, and there may be one or several. Kidney stones usually affect adults over age 30, of both sexes, but more often occur in men.
Signs & Symptoms
Episodes of severe, colicky (intermittent) pain every few minutes. The pain usually appears first in the back, just below the ribs. Over several hours or days, the pain follows the stone’s course through the ureter toward the groin. Pain stops when the stone passes.
- Frequent nausea.
- Traces of blood in urine. Urine may appear cloudy or dark.
Excess calcium in the urine caused by disturbance in the parathyroid gland, which upsets calcium metabolism or by excess calcium or vitamin D intake.
- Gout (uric-acid stones).
- Blockage of urine from any cause.
- Decreased urine volume due to dehydration or hot, dry weather.
- Improper diet (too much calcium).
- Family history of kidney stones.
- Excess alcohol consumption.
- Bed confinement for any reason.
- Geographical living area (southeastern U.S.).
- Strain all urine through filter paper or gauze to detect passage of the stone; or urinate into a glass jar, look for and recover any stone and discard the urine. Take stone to the doctor for composition analysis.
- Diagnostic tests may include urinalysis and urine culture, Xray of the abdomen, kidney ultrasound, CT scan, and intravenous urography (method of studying the kidneys and urinary tract by injecting a medication into the bloodstream that X-rays can detect).
- Small solitary stone, uncomplicated by obstruction or infection, may need no specific treatment.
Treatment to remove larger stones, if they don’t pass spontaneously, and are causing complications, infection or severe pain. Options include chemical dissolution, endourologic stone extraction, percutaneous nephrolithotomy, extracorporeal shock wave lithotripsy, and rarely, open surgery. Other, new approaches are also under development.
- Stones due to excess calcium in the body may require surgical removal of abnormal parathyroid tissue.
- Pain relievers.
- Antispasmodics to relax the ureter muscles and help the stone pass.
- Depending on the type of stone (calcium-containing, struvite stones, cystine stones, uric acid or other composition), medication may be prescribed that will stop the growth of existing stones or new stones. This often involves a prolonged program, and your compliance is important.