pertaining to the kidney; called also nephric. renal clearance tests laboratory tests that determine the ability of the kidney to remove certain substances from the blood. The most commonly used is the creatinine clearance test, which is a measure of the glomerular filtration rate. Renal physiology is the study of kidney function. Nephrology is the medical specialty that addresses diseases of kidney function: these include CKD, nephritic and nephrotic syndromes, acute kidney injury, and pyelonephritis. Healthy kidneys do many important jobs. They remove wastes and extra fluid from your body, help make red blood cells, keep bones strong, and work to maintain the right amount of minerals in your blood. Properly functioning kidneys are critical for maintaining good health. Diabetes, high blood pressure, or family history can increase risk of kidney disease. Healthcare professionals can find kidney disease through blood and urine tests. These tests look for high levels of waste in the blood or unusual things in the urine, such as protein or tiny amounts of blood. They also might use tests such as ultrasound or CT scans to look at the kidneys. Kidney (renal) capsule: This has three layers of connective tissue or fat that cover your kidneys. It protects your kidneys from injury, makes them more stable and connects your kidneys to nearby tissues. Much of renal physiology is studied at the level of the nephron, the smallest functional unit of the kidney. Each nephron begins with a filtration component that filters the blood entering the kidney. RENAL definition: 1. relating to the kidneys (= body organs): 2. relating to the kidneys (= body organs). Learn more. The meaning of RENAL is of, relating to, involving, or located in the region of the kidneys : nephric. How to use renal in a sentence. Renal system, in humans, organ system that includes the kidneys, where urine is produced, and the ureters, bladder, and urethra for the passage, storage, and voiding of urine. Learn more about the structure and function of the renal system in this article.