Kidney stones

CONDITION

Kidney stones are deposits of minerals that form in the urinary tract. They occur when the concentration of substances that form these crystals (such as calcium, oxalate and uric acid) in the urine are too great. These crystals stick together forming increasingly larger particles. Kidney stones affect more than 1 in 10 people.

Many small kidney stones do not cause any symptoms. As stones get larger they may cause blood in the urine or urinary tract infections. Stones can also move and cause a blockage, either within the kidney or in the ureter (the tube that drains urine from the kidney down to the bladder) and can then cause severe pains and infections, which can become very serious if not diagnosed and treated promptly.

Small, asymptomatic kidney stones can be often be left alone, or monitored with scans without the need for treatments. Obstructing stones can sometimes be left to pass spontaneously, if the pains are well controlled and if there is no sign of infection; this will depend on the size and the location of the stones also.

Stones can be treated with either extracorporeal shock wave lithotripsy (ESWL), ureteroscopy and ureterorenoscopy and holmium laser fragmentation or percutaneous nephrolithotomy (PCNL). About 10% of stones are made from uric acid; these can sometimes be treated with medical therapy instead of a surgical intervention.

Once stones have been treated investigations looking into why the stones have formed are undertaken. These can sometimes reveal a biochemical abnormality or underlying medical issue which, if treated, can reduce the frequency at which stones form in the future.