KIDNEY STONES
Kidney stones or renal calculi are solid concretions or calculi (crystal aggregations) formed in the kidneys from dissolved urinary minerals. Nephrolithiasis refers to the condition of having kidney stones. Urolithiasis refers to the condition of having calculi in the urinary tract (which also includes the kidneys), which may form or pass into the urinary bladder. Ureterolithiasis is the condition of having a calculus in the ureter, the tube connecting the kidneys and the bladder.
Kidney stones typically leave the body by passage in the urine stream, and many stones are formed and passed without causing symptoms. If stones grow to sufficient size before passage – on the order of at least 2-3 millimeters – they can cause obstruction of the ureter. The resulting obstruction causes dilation or stretching of the upper ureter and renal pelvis (the part of the kidney where the urine collects before entering the ureter) as well as muscle spasm of the ureter, trying to move the stone. This leads to pain, most commonly felt in the flank, lower abdomen and groin (a condition called renal colic). Renal colic can be associated with nausea and vomiting. Stones in any part of the urinary tract can cause damage to the lining of the urinary tract, with blood in the urine. The blood may be visible with the naked eye (macroscopic hematuria) or under the microscope (microscopic hematuria). (Sources: Medline Plus/ Wikipedia)
