Kidney stones are solid mineral deposits that form inside of kidneys.
Some kidney stones are small enough that they can be passed with little more than some temporary discomfort. Other mineral deposits are sizeable enough that medical attention is needed to prevent urinary infections or obstructions and similar complications.
It's also possible for kidney stones to become trapped in other parts of the urinary system, including the bladder and the urine tubes (ureters and the urethra).
Some kidney stones don't produce symptoms until they get into other parts of the urinary system beyond the kidneys. Stones that produce symptoms may result in pain that's felt in the back or on the sides of the body below the ribs. In addition to painful urination, symptoms related to kidney stones may include:
Radiating pain felt in the lower abdomen and groin
Periodically recurring pain
Discolored, cloudy, or foul-smelling urine
Increasingly frequent urination
Nausea and vomiting
Fever and chills if kidney stones are related to an infection
Types of Kidney Stones
Most kidney stones are classified as calcium stones, which are largely caused by certain foods with a high concentration of naturally occurring substances called oxalates. Struvite stones are related to infections. Uric acid stones may form in gout sufferers or individuals who don't get sufficient fluids. And finally, hereditary disorder called cystinuria that results in the excessive production of certain amino acids is what can result in cystine stones.
Diagnosis & Treatment
Other than a physical exam and a review of a patient's medical history, diagnosing kidney stones typically involves a series of tests. Blood tests can provide information about kidney health and calcium or uric acid levels. Usually involving urine tests taken over a two-day period, a 24-hour urine collection test may be done to determine the level of stone-forming minerals being produced. X-rays and a CT urogram are among the types of image tests that may be performed to help make a positive diagnosis of kidney stones.
Smaller stones not producing significant symptoms may be treated with pain-relieving medications, encouraging the consumption of more water, and medications called alpha blockers to help relax muscles around the tube that goes from a kidney to the bladder (ureter). Larger and problematic kidney stones may be treated in several ways.
With a procedure known as extracorporeal shock wave lithotripsy, sound waves are used to break up the stones. With percutaneous nephrolithotomy, small telescopes and instruments are used to surgically remove kidney stones. Stones may also be removed with the use of a special lighted tube attached to a camera called a ureteroscope, which is inserted through the urine tube that leads to the outside of the body (urethra). Parathyroid gland surgery may be necessary to treat calcium phosphate stones.
Anyone can develop kidney stones at any age. However, there are certain risk factors that may increase the risk of having problematic mineral deposits in one or both kidneys. For instance, having a family or personal history of kidney stones increases the odds of having them. The absorption of calcium and water that can lead to kidney stone formation may also be affected by inflammatory bowel disease (IBD), chronic diarrhea, and gastric bypass surgery. Preventative measures often recommended include drinking more water, maintaining a healthy weight, and avoiding foods high in sodium, protein, and sugar.