The location of the kidneys: The right renal hilus targets the transverse process of the second lumbar vertebra, and the left renal hilus targets the transverse process of the first lumbar vertebra. The right kidney is slightly lower than the left kidney by 1-2 cm due to the relationship with the liver. Normal kidney movement up and down is within 1-2 cm. The kidneys are under the diaphragm. During physical examination, except that the lower pole of the right kidney can be palpated at the lower edge of the ribs, the left kidney is not easy to feel.

The kidneys are located on both sides of the spine, close to the posterior abdominal wall, and behind the peritoneum. The upper end of the left kidney is level with the lower edge of the 11th thoracic vertebra, and the lower end is level with the lower edge of the 2nd lumbar vertebra. The right kidney is half a vertebra lower than the left kidney. The left 12th rib runs obliquely across the middle part behind the left kidney, and the right 12th rib runs obliquely across the upper part behind the right kidney.

The body surface projection of the renal hilum: on the anterior abdominal wall, it is located at the front end of the 9th rib, and on the posterior abdominal wall, it is located at the intersection of the lower edge of the 12th rib and the outer edge of the erector spinae muscle. This angle is called the renal angle or Back support angle. In kidney disease, there is often tenderness or percussion pain here.

Surface projection of the kidney: Draw two vertical lines at 2.5cm and 7.5-8.5cm on both sides of the posterior midline, passing through the spinous processes of the 11th thoracic vertebra and the 3rd lumbar vertebra. A horizontal line, the kidney is located within the two quadrilaterals formed by this vertical and horizontal marking line

. If there are abnormal symptoms such as pain within this range, it often indicates kidney disease. The location of the kidney may vary. If it is located in the pelvis or iliac fossa, it is a low-lying kidney; if it moves across the midline to the opposite side, it is a crossed ectopic kidney. Abnormal kidney position is relatively rare.

In the diagnosis of abdominal masses, attention should be paid to distinguishing them from tumors.

Clinically, the area between the lateral edge of the erector spinae muscle and the 12th rib is often called the kidney area (spinal costal angle). When the kidneys are diseased, this area is often touched or percussed. There is tenderness or throbbing pain.