Kidney stone disease

Kidney stones are solid accretions (crystals) of dissolved minerals in urine found inside the kidneys. Kidney stones typically leave the body in the urine stream; if they grow relatively large before passing, their jagged crystalline shape can cause severe pain in the ureters and urethra. Because the urethra is longer in males than in females, kidney stones are more likely to be a severe problem for men than for women.

Consumption of too much calcium can aggravate the development of kidney stones, since the most common type of stone is calcium oxalate. There are many other types of kidney stone, and a person may be susceptible to only some of them.

Treatments include dietary modifications (including the advice to drink plenty of water), medications, and use of a lithotriptor. Surgery is rarely used to remove kidney stones; instead pain management is used while waiting for the stone to pass on its own.

Kidney stones are unrelated to gall stones.

Isaac Asimov suffered from kidney stones, and wrote about how his pain was treated with morphine, saying that he feared becoming addicted to it if he ever needed it again.

• http://www.methodisthealth.com/urogen/stones.htm - Info on the disorder
• http://www.herringlab.com/photos/ - Pictures of kidney stones, showing their crystalline shape