The renal artery is a large blood vessel that supplies each kidney. This vessel branches off from the primary artery of the heart, known as the aorta. The role of the renal artery is to supply clean, oxygen-rich blood to each of the two kidneys. It is interesting to note that the blood supply to the kidney can be variable, and as such, there may sometimes be more than one renal artery supplying each kidney.

The renal artery in the right kidney is generally longer than the one in the left kidney. This is due to the positioning of the kidney itself as well as the aorta and the superior vena cava. The superior vena cava is a large vein that carries blood to the right side of the heart after the cells and tissues of the body have absorbed the oxygen and other nutrients from the blood.

The right renal artery travels behind the veins known as the inferior vena cava and the right renal vein. This artery then travels behind the pancreas as well as the duodenum. The pancreas is an organ that contributes to both the digestive and endocrine systems of the body. The duodenum is the beginning segment of the small intestine.

The left renal artery is situated a bit higher than the artery on the right. This artery is found behind the left renal vein, the pancreas, and the splenic vein. The splenic vein is the blood vessel responsible for draining the blood from the spleen. The inferior mesenteric vein crosses the left renal artery. This blood vessel has the role of draining blood from the large intestine.

Renal artery stenosis is a common medical issue affecting the renal arteries. In this condition, the artery becomes narrowed, preventing proper blood flow to the kidney. High blood pressure often occurs once the artery becomes too narrow for blood to flow freely. Kidney atrophy sometimes occurs as a result of this medical condition as well. When this occurs, some of the kidney tissue begins to waste away due to the lack of sufficient blood flow, often dramatically decreasing the size and sometimes the functioning of the kidney.

Treatment options for stenosis of the arteries in the kidney depend upon the particular symptoms suffered by the patient as well as whether kidney function has been affected. Since high blood pressure is so common among those suffering from this condition, controlling the patient's blood pressure is generally the first course of treatment. Occasionally, surgery to expand the artery may become necessary.