Kidney stones, also known as renal calculi, form in the kidneys from minerals in urine. There are five main types of kidney stones, with calcium oxalate being the most common at 80%. Risk factors include an imbalanced pH in urine and certain medical conditions. Symptoms include severe side and back pain, pain when urinating, nausea, and blood in the urine. Diagnostic tests include urine analysis, CT scans, x-rays, and ultrasounds. Treatment involves pain medication, increased fluids, shockwave lithotripsy, or surgery to remove the stones.