Renal calculi, also known as kidney stones, are hard, pebble-like deposits that form in the kidneys. They are made up of mineral and acid salts, and can vary in size and shape. They can form when the urine becomes too concentrated, allowing the minerals to crystallize and stick together.

Symptoms of kidney stones can include:

  • Severe pain in the back, side, lower abdomen, or groin
  • Blood in the urine
  • Nausea and vomiting
  • Cloudy or strong-smelling urine
  • Frequent urination or difficulty urinating

Kidney stones can occur in anyone, but certain factors can increase the risk, such as:

  • Family history of kidney stones
  • Dehydration
  • Certain medical conditions, such as gout or inflammatory bowel disease
  • Certain medications, such as diuretics or calcium-based antacids