What Is the Renal Artery and What Does It Do?

The renal artery is the main blood vessel that supplies each kidney with the oxygen-rich blood it needs to function. You have two renal arteries—one for each kidney—branching off from the abdominal aorta, the body’s largest artery.

The primary job of the renal artery is to deliver blood to the kidneys for filtering. Every minute, roughly 20 to 25 percent of the blood pumped by your heart goes to the kidneys through these arteries. That adds up to about 1.2 liters (1.3 quarts) of blood every minute. This constant flow is what allows your kidneys to filter waste, remove excess water, and maintain a healthy balance of salts and other important substances.

Once the renal artery reaches the kidney, it branches into smaller vessels that reach the nephrons, the tiny filtering units inside the kidney. These filters work on the blood that the renal artery delivers, removing waste and forming urine. Cleaned blood then exits the kidney through the renal vein and returns to the rest of the body.

Because the kidneys depend on a steady blood supply, any blockage or narrowing of the renal artery—known as renal artery stenosis—can reduce kidney function. This can also cause high blood pressure, since the kidneys respond to low blood flow by releasing hormones that raise it.

The renal artery may not get much attention, but it is a vital part of how the kidneys—and the entire body—stay healthy. Without it, the kidneys would not receive the fuel they need to do their job.

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