Urinary stone disease

Urinary stones form in the kidney or the urinary bladder. Their size ranges from fine sandy grains to large, coral-like stones. Most urinary stones are composed of calcium oxalate. Other components include uric acid, cystine, and calcium phosphate. Stone formation is a result of an accumulation of these substances in the urine. Underlying causes usually include metabolic disorders, too little liquid uptake, lack of exercise, wrong diet and urinary tract disorders. The considerable increase of urinary/kidney stone disorders in the last 30 years is the result of our prosperity. In 2000, there were approx. 1.2m cases of kidney/urinary stones. Men were affected twice as often as women. Many patients are prone to recurring stone formation.

A liquid uptake of 2.5 – 3 litres per day sufficiently dilutes the urine and lowers the risk of stone formation. Patients should spread their liquid uptake evenly out over the entire day. In order to make recommendations for a specific diet the exact composition of the stones must be determined first.

Symptoms range from a mild dragging pain in the side to severe bouts of renal colic with nausea and vomiting. Stones located in the lower third of the urethra often cause pain that extends into the testicles or labia. Most feared are infections of the urine collecting above a blockage caused by a stone. Such infections require immediate medical intervention.

Urinalysis often finds microscopically small traces of blood. Ultrasound can show the collection of urine in the affected kidney. X-rays can also be used to produce images of stones located in the urinary tract. Computed tomography is another useful diagnostic tool.

80 % of all stones pass spontaneously without any intervention. These cases usually require only adequate pain therapy. Liquid uptake, lots of exercise and hot baths may also facilitate stone passage. An acute colic, however, requires intravenous application of painkillers and muscle relaxants. If urine retention causes urinary tract infection, quick intervention is of the essence to retain the diseased kidney. Urine passage from the affected kidney must be ensured by temporary drainage. If the stone does not pass spontaneously, it can be treated with shock wave lithotripsy or minimally invasive surgical procedures..