Learn what causes kidney stones, symptoms, treatments, and how to prevent them with a personalized plan. Kidney stones form when there is a decrease in urine volume and/or an excess of stone-forming substances in the urine. Read about kidney stone (nephrolithiasis) pain, symptoms, diagnosis, treatment, surgery, causes, types, diet, and more. Have you ever wondered how people get kidney stones? If so, you’re not alone. While kidney stones are common and painful, many people don’t know what causes them or how to prevent them. You get kidney stones when your pee has a high concentration of minerals and other substances--like calcium, oxalate, and uric acid--that come together to make crystals. What are kidney stones? Kidney stones are solid masses or crystals that form from substances (like minerals, acids and salts) in your kidneys. They can be as small as a grain of sand or — rarely — larger than a golf ball. Kidney stones are also called renal calculi or nephrolithiasis. Kidney stone disease or urinary stone disease is a crystallopathy that occurs when there is an excess of minerals in the urine and not enough liquid or hydration. This imbalance causes tiny crystals to aggregate and form hard masses, or calculi (stones), in the upper urinary tract. Find out about kidney stones, including what the symptoms are, what causes them, how they're treated and how to prevent them. Kidney stones form when urine becomes concentrated, allowing crystals to develop. While you might be able to pass a kidney stone on your own at home, if you’re in extreme pain and have a fever, you should seek medical care. Passing a kidney stone involves four stages, from formation to exit. The main symptom of kidney stones is pain in your back, abdomen, or side. Some other symptoms include cloudy urine, a burning sensation when you urinate, and nausea. Kidney stones can affect any of the organs that make urine or remove it from the body — from the kidneys to the bladder. Often, stones form when the urine has less water in it.