- What they are: Solid, pebble-like mineral deposits that form in the kidneys.
- The Cause: Urine that contains excessively high levels of crystal-forming substances, most notably calcium, oxalate, and uric acid.
- Key Symptoms:
- Severe, waves of cramping pain in the back and side (flank) that can spread to the lower abdomen or groin.
- Blood in the urine (making it look pink, red, or cola-colored).
- Nausea and vomiting.

