In humans, the liver is located on the right side of the body above the large and small intestines and below the diaphragm and heart. The two kidneys are located on either side of the body behind the intestines and below the liver.
Both the liver and kidneys are essential organs that are required to sustain life. The liver is a gland that purifies toxins from the body and secretes bile to break down fats. When the liver is damaged, a yellowing of the skin and eyes occurs. This jaundiced state can be brought on by excessive alcohol ingestion or infection with the viruses hepatitis B or C. The liver is one of the few organs that can regenerate itself, though once a certain threshold of damage is reached, a liver transplant is needed.
The kidneys are filtration organs that excrete and reabsorb many nutrients and minerals from the blood and urine. Each kidney contains thousands of nephrons that contain channels and transporters to exchange micromolecules from the urine to the blood. Kidney damage reduces the ability of the body to excrete molecules, such as molecules of medications. Certain medication doses need to be reduced in patients with kidney function impairment.