The kidneys are located in the posterior abdomen, positioned retroperitoneally (behind the peritoneum) on either side of the spine. They typically extend from the level of the 12th thoracic vertebra (T12) down to the 3rd lumbar vertebra (L3). The right kidney is usually slightly lower than the left due to the presence of the liver. Both kidneys lie just below the rib cage, with one kidney on each side of the spine. The upper parts of the kidneys are partially protected by the 11th and 12th ribs. Each kidney is surrounded by layers of fat and fascia, and the adrenal glands sit immediately superior to them