The liver and kidneys both "clean" the blood by removing wastes and toxins but do so in different ways. The kidneys remove wastes to the urine while the kidneys remove wastes to the intestinal tract. When these organs fail, the patient may go for years without experiencing any symptoms. However, as the failure progresses, the symptoms may become more severe. While the liver and kidneys are located in different areas of the body, and perform different functions, failure in either organ can produce similar symptoms.
Urinary and Stool Changes
Both kidney and liver failure can affect the urine. With kidney failure, the patient may urinate more often, experience changes in urine volume or urinate more at night. With liver failure, the urine may get darker because the kidneys have to filter out the wastes that the liver missed. Liver and kidney failure will affect the stools, making them pale or bloody and tar-coloured.
Swelling, Abdominal Pain and Back Pain
Kidney failure often manifests as swelling in the extremities, especially the hands, ankles and feet. Patients in kidney failure may also experience swelling in the face. With liver failure, the swelling occurs in the abdomen, a condition called ascites. Patients in liver failure may experience abdominal pain along with the swelling. With kidney failure, the pain may occur in the mid to lower back and side. Patients in kidney failure can also experience headaches and muscle cramps.
Itching, Nausea, Metallic Taste and Loss of Appetite
Failure of either organ can cause wastes and toxins to build up in the body. These wastes may be excreted through the skin, causing itching. Patients in kidney failure may also experience a metallic taste in the mouth as the toxins excrete through the salivary glands. Both liver and kidney patients may experience nausea and loss of appetite.
Shortness of Breath and Fatigue
Kidney failure can cause fluid to build up in the lungs, leading to shortness of breath. The kidneys also produce a hormone called erythropoietin, which helps make red blood cells. Kidney failure means less hormone and fewer red blood cells---a condition called anaemia---which causes fatigue. Chronic fatigue is also a symptom of liver failure.
Bruising, Bleeding and Jaundice
Patients in kidney failure may bruise very easily, and extensively, and have trouble controlling bleeding. Both kidney and liver failure can lead to jaundice---a yellowing of the skin caused by excess bilirubin in the blood.