Kidney Stones

Kidney stones, or renal calculi, are solid concretions of dissolved minerals in urine; calculi typically form inside the kidneys or ureters. The terms nephrolithiasis and urolithiasis refer to the presence of calculi in the kidneys and urinary tract, respectively. Renal calculi can vary in size from as small as grains of sand to as large as grapefruit. 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 they can cause obstruction of the ureter. The resulting distention with urine can cause severe episodic pain, most commonly felt in the flank, lower abdomen and groin. Renal colic can be associated with nausea and vomiting due to the embyrological association of the kidneys and the intestinal tract. Recurrence rates are estimated at about 10% per year.

Kidney stones are usually asymptomatic until they obstruct the flow of urine. Symptoms can include acute flank pain, nausea and vomiting, restlessness, dull pain, hematuria, and possibly fever if an infection is present. Acute renal colic is described as one of the worst types of pain that a patient can suffer. Note that the pain is generally due to the stone's presence in the ureter, and not—as is commonly believed—the urethra and lower genitals.

...More at Wikipedia  

Related Links:

• US National Library of Medicine
• Mayo Clinic

Recent Hope Cube Blog Entries For Kidney Stones