Hi, You need not worry much about a single kidney stone which you have already passed. Please take the following precautions to prevent further stone formation: 1. Drink lot of fluids (as much to keep your urine always colorless) 2. Reduce sodium intake to less than 2.3 g 3. Reduce animal protein intake to less than 6 ounces per day 4. Take lot of citrus fruits 5. Reduce chocolates, soft drinks, tea, coffee and nuts Get an ultrasonogram after about 6 months to look for any new stone formation. If you are still worried, you can consult a Urologist for kidney stone. I am available to answer any more queries you may have, Wish you good health, Dr. Raguram.