The presence of calculi (or stones) in the kidney is called renal lithiasis. It is estimated that around 5 or 6% of the population suffers from it. If it is not treated properly, it can result in various kinds of kidney failure.



Lithiasis is caused by a high concentration in the urine of certain substances, such as phosphates, purines and, in particular, calcium. This concentration may, of course, be due to an excessive intake of these elements or due to their poor metabolisation, but also due to a decrease in the intake of fluids.



When the stones are small they can be asymptomatic. In many cases, the stones are expelled spontaneously, which may block urine output, then producing renal colic. Both the symptoms and the consequences of this condition will depend to a great extent on the size and characteristics of the stones.

  • Haematuria: When a stone is expelled, it can cause lesions along the way until it reaches the urinary tracts and, as a result, bleeding that will show up in the urine.
  • Urinary infections: They can be a symptom of renal lithiasis, but they can also be one of its causes.
  • Renal colic: This is usually very painful. It starts in the lower back and spreads along the back and abdomen, to the genitals.

It is accompanied by other symptoms such as a fever, sweats, vomiting, etc.



Fortunately, in the vast majority of cases, the stones are expelled naturally, although sometimes these remain trapped because of their shape, size and position. In these cases, the following treatments can be used:

  • Potassium citrate.- This compound is effective only to dissolve uric acid stones.
  • Extracorporeal shock wave lithotripsy.- It is possible to break large stones into much smaller pieces, which are able to pass out through the urinary tracts, using shock waves. The stones are located using ultrasound or X-rays, systems that will serve as a guide for the shock waves.

The procedure is performed with anaesthesia or under sedation in less than an hour, and it can involve the placement of a probe up to the kidney to help a faster and effective elimination of the remains of stones. Drinking a lot of water after the procedure is recommended.

  • Percutaneous nephrolithotomy.- A nephroscope is introduced though the skin up to the stone. With this tool, which will be guided with the help of radioscopy, first it will be possible to break the stone and then extract the remains.
  • Ureteroscopy.- This is a procedure with endoscopy, accessing through the urinary ducts.
  • Urology