Kidney stones

Kidney stones occur due to the deposition and crystallisation of mineral salts in the urine. The most common of these is calcium oxalate; however, uric acid stones or calcium phosphate stones also occur. If the stones pass through the narrow ureter or get stuck there, this causes severe pain, i.e. renal colic. Kidney stones can be treated with medication, with surgery or by destroying them with sound waves.

The formation and deposition of kidney stones is facilitated by different circumstances. Besides a genetic predisposition, factors which increase the salt and mineral concentration of the urine play a particular role in this. They include excessive sweating, insufficient fluid intake or obstruction of the outflow of urine. Dietary habits also contribute somewhat. A high-protein diet and food with a high percentage of oxalate (chocolate, rhubarb, beetroot and spinach) can facilitate the occurrence of kidney stones.

Kidney stones usually only cause symptoms if the stones pass through the narrow ureter or get stuck there. Then this causes the typical renal colic with severe, cramp-like pain in the area of the kidneys. Renal colic is often accompanied by nausea, vomiting and fever. The severe pain can lead to paralysation of the bowel and a bloated abdomen. Symptoms when urinating or blood in the urine can be further signs of kidney stones. Such symptoms should therefore always be checked by a doctor. In rare cases, they can be caused by a tumour. Kidney stones can also facilitate the occurrence of renal bed inflammation.

Kidney stones are diagnosed on the basis of the typical symptoms and with a urine examination. Where necessary, additional examinations such as an ultrasound, computed tomography, a cystoscopy or a ureterorenoscopy are carried out.

Depending on the situation, different treatment options come into consideration. Generally: Drink large amounts of fluid to flush out the stones. Uric acid stones can be dissolved with stone-dissolving medications (litholysis). Oxalate stones, which are the most common, are not dissolved with medication. In this case, surgical removal is considered. Surgical removal of kidney stones is usually done endoscopically via a cystoscopy or a ureterorenoscopy, often with the necessary laser fragmentation.

Bladder stones can also be destroyed with sound waves as an alternative to surgery. Extracorporeal shock wave lithotripsy (ESWL) involves destroying the stones with focused sound waves from outside the body. The resulting smaller pieces are then excreted via the urine.

The likelihood of kidney stones recurring is relatively high. Therefore, preventive measures are recommended. The most important preventive measures include drinking a lot of water (2–3 litres per day), adjusting your food intake (less protein, lots of vegetables and fruits) and sufficient exercise.