The renal capsule is a tough fibrous layer surrounding the kidney and covered in a layer of perirenal fat known as the adipose capsule of kidney.

Overlying the renal fascia and between this and the transverse fascia is a region of pararenal fat.

[2] Stretching of the renal capsule due to swelling of the kidney causes flank pain.

[3] The renal capsule surrounds the functional tissue of the kidney, and is itself surrounded by a fatty adipose capsule, fascia, and fat.

From the inner part of the kidney to outside the kidney, the positioning of the capsule is: Sometimes the adipose capsule of the kidney also known as the perirenal fat, is regarded as a part of the renal capsule.