Where is the kidney located?

Many people are unaware of the precise location of the kidneys in the human body. The kidneys lie on either side of the spine, adjacent to the posterior abdominal wall and situated retroperitoneally (i.e., behind the peritoneum).

Where Are the Kidneys Located?

The kidneys are vital organs responsible primarily for urine production and the elimination of metabolic waste products and toxins from the body. Anatomically, they reside retroperitoneally—on both sides of the vertebral column, close to the posterior abdominal wall and posterior to the peritoneum. The right renal hilum faces the transverse process of the second lumbar vertebra (L2), whereas the left renal hilum faces the transverse process of the first lumbar vertebra (L1). Due to the presence of the liver, the right kidney lies approximately 1–2 cm lower than the left kidney. Under normal physiological conditions, the kidneys exhibit slight vertical mobility—moving up and down by about 1–2 cm—and are located inferior to the diaphragm. Clinically, the area bounded laterally by the lateral border of the erector spinae muscle and superiorly by the 12th rib is termed the “renal angle” or “kidney region.” When renal pathology is present, percussion tenderness or direct tenderness may be elicited in this region.

The kidneys serve two major physiological functions. First, their excretory function involves eliminating metabolic waste products from the body via urine formation; regulating the homeostasis of electrolytes—including sodium, potassium, and calcium chloride; and maintaining acid-base balance—thereby ensuring overall internal environmental stability. Second, the kidneys act as endocrine organs: they secrete erythropoietin to maintain stable hemoglobin levels; produce active vitamin D₃ (calcitriol) to support normal bone metabolism; and release vasoconstrictive and vasodilatory substances essential for blood pressure regulation.

In traditional Chinese medicine, the kidneys are regarded as the “root of life,” and the essence stored within the kidneys (“kidney essence”) is considered the fundamental source of vitality. We hope this explanation has been helpful to you.