Kidney stones form in the kidney. If they stay in the kidney, they do not typically cause pain. Kidney stones are small "pebbles" of salt and mineral in the urine. The most common symptom is severe pain. Most stones pass on their own, but medical procedures may be needed to remove some kidney stones. When they travel out of the body through the tubes of the urinary tract (including the ureters, which connect the kidney to the bladder, or the urethra, which leads outside the body), their movement may cause:
No symptoms, if the stone is small enough.
Sudden, severe pain that gets worse in waves. Stones may cause intense pain in the back, side, abdomen, groin, or genitals. People who have had a kidney stone often describe the pain as "the worst pain I've ever had."
Feeling sick to the stomach (nausea) and vomiting.
Blood in the urine (hematuria), which can occur either with stones that stay in the kidney or with those that travel through the ureters.
Frequent and painful urination, which may occur when the stone is in the ureter or after the stone has left the bladder and is in the urethra. Painful urination may occur when a urinary tract infection is also present.
Risk factors you can control
Risk factors for both new and recurring kidney stones that you can control include: Fluids you drink. The most common cause of kidney stones is not drinking enough water. Try to drink enough water to keep your urine clear (about 8 to 10 glasses of water a day). Drinking grapefruit juice may increase your risk for developing kidney stones.
Diet. If you think that your diet may be a problem, schedule an appointment with a dietitian and review your food choices. Vitamins C and D can increase your risk of kidney stones when you take more than the daily recommendations. Read supplement labels carefully, and do not take more than the recommended daily doses. Levels of calcium affect your risk of kidney stones. Getting your recommended amounts of calcium combined with a low-sodium, low-protein diet may decrease your risk of kidney stones. Diets high in protein, sodium, and oxalate-rich foods, such as dark green vegetables, increase your risk for developing kidney stones.
Weight and weight gain. Weight gain can result in both insulin resistance and increased calcium in the urine, which can result in a greater risk for kidney stones. In one study, weight gain since early adulthood, a high body mass index (BMI), and a large waist size increased a person's risk for kidney stones.
Activity level. People who are not very active may have more problems with kidney stones.
Medicine. Some medicines, such as acetazolamide (Diamox), or indinavir (Crixivan), can cause kidney stones to form.