Kidney stones are frequently described as one of the most painful things a person can experience. Many say they are worse than childbirth. The stones are solid crystallized masses made from minerals. Small stones may be passed naturally when you urinate, but if the stones grow big enough, they block the ureter, causing severe pain.
Extreme, sharp, cramping pain is often the first symptom, felt in the lower back and side, and later radiating to the groin. The pain comes in waves as the body attempts to expel the stone.