A kidney stone forms when urine gets too concentrated. Here is the twist that is easy to miss. A stone sitting in the kidney often causes no pain. The agony starts only when it drops into the narrow ureter. And if it gets stuck, urine backs up and swells the kidney (hydronephrosis). Click each stage.
Where is the stone?
Pain level—
Pick a stage to see what happens.
Pick a stageFollow the stone
👆 Where is it?
What is happening
Risk & prevention
Risk factors:hypercalcemia (hyperparathyroidism or a parathyroid tumor), high uric acid, and dehydration. Prevention is simple: drink plenty of water. Dilute urine keeps crystals from clumping into stones and helps flush small ones out.