Also called: Nephrolithiasis
A kidney stone is a solid piece of material that forms in the kidney from substances in the urine. It may be as small as a grain of sand or as large as a pearl. Most kidney stones pass out of the body without help from a doctor. But sometimes a stone will not go away. It may get stuck in the urinary tract, block the flow of urine and cause great pain.
The following may be signs of kidney stones that need a doctor’s help:
- Extreme pain in your back or side that will not go away
- Blood in your urine
- Fever and chills
- Urine that smells bad or looks cloudy
- A burning feeling when you urinate
Your doctor will diagnose a kidney stone with urine, blood, and imaging tests.
If you have a stone that won’t pass on its own, you may need treatment. It can be done with shock waves; with a scope inserted through the tube that carries urine out of the body, called the urethra; or with surgery.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
Cystinuria is a condition characterized by the buildup of the amino acid cystine, a building block of most proteins, in the kidneys and bladder. As the kidneys filter blood to create urine, cystine is normally absorbed back into the bloodstream. People with cystinuria cannot properly reabsorb cystine into their bloodstream, so the amino acid accumulates in their urine.As urine becomes more concentrated in the kidneys, the excess cystine forms crystals. Larger crystals become stones that may lodge in the kidneys or in the bladder. Sometimes cystine crystals combine with calcium molecules in the kidneys to form large stones. These crystals and stones can create blockages in the urinary tract and reduce the ability of the kidneys to eliminate waste through urine. The stones also provide sites where bacteria may cause infections.