Kidney stones are small masses of salts and minerals that form inside the kidneys and may travel down the urinary tract. Kidney stones range in size from just a speck to as large as a ping pong ball. Signs and symptoms of kidney stones include blood in the urine, and pain in the abdomen, groin, or flank. About 5% of people develop a kidney stone in their lifetime.
The kidneys regulate levels of fluid, minerals, salts, and other substances in the body. When the balance of these compounds changes, kidney stones may form. There are four types of kidney stones, each made of different substances. Uric acid and cystine are two compounds that may comprise kidney stones. Factors known to increase the risk of kidney stones include dehydration, family history, genetics, and the presence of certain medical conditions. Having one or more family members with a history of kidney stones increases the risk of the condition.
Many kidney stones are painless until they travel from the kidney, down the ureter, and into the bladder. Depending on the size of the stone, movement of the stone through the urinary tract can cause severe pain with sudden onset. People who have kidney stones often describe the pain as excruciating. The lower back, abdomen, and sides are frequent sites of pain and cramping. Those who have kidney stones may see blood in their urine. Fever and chills are present when there is an infection. Seek prompt medical treatment in the event of these symptoms.