Liver Disease
(Hepatic Disease)

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Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Bhupinder Anand, MD

• The liver plays an important role in many bodily functions from protein production and blood clotting to cholesterol, glucose and iron metabolism.
• A variety of illnesses can affect the liver.
• Cirrhosis occurs when normal liver cells are replaced by scar tissue as a result of chronic liver disease.
• Symptoms of liver diseases include weakness and fatigue, weight loss, nausea, vomiting, and yellow discoloration of the skin (jaundice).
• The treatment of a particular liver disease depends on its specific cause.

Liver disease is any disturbance of liver function that causes illness. The liver is responsible for many critical functions within the body and should it become diseased or injured, the loss of those functions can cause significant damage to the body. Liver disease is also referred to as hepatic disease.

Liver disease is a broad term that covers all the potential problems cause the liver to fail to perform its designated functions. Usually, more than 75% or three quarters of liver tissue needs to be affected before decrease in function occurs.

The liver is the largest solid organ in the body; and is also considered a gland because among its many functions, it makes and secretes bile. The liver is located in the upper right portion of the abdomen protected by the rib cage. It has two main lobes that are made up of tiny lobules. The liver cells have two different sources of blood supply. The hepatic artery supplies oxygen rich blood that is pumped from the heart, while the portal vein supplies nutrients from the intestine and the spleen.

Normally, veins return blood from the body to the heart, but the portal vein allows chemicals from the digestive tract to enter the liver for "detoxification" and filtering prior to entering the general circulation. The portal vein also efficiently delivers the chemicals and proteins that liver cells need to produce the proteins, cholesterol, and glycogen required for normal body activities.

As part of its function, the liver makes bile, a fluid that contains among other substances, water, chemicals, and bile acids (made from stored cholesterol in the liver). Bile is stored in the gallbladder and when food enters the duodenum (the first part of the small intestine), bile is secreted into the duodenum, to aid in the digestion of food.

Picture of the Liver

The liver is the only organ in the body that can easily replace damaged cells, but if enough cells are lost, the liver may not be able to meet the needs of the body.

The liver can be considered a factory; and among its many functions include the following:

• production of bile that is required in the digestion of food, in particular fats;
• storing of the extra glucose or sugar in the body into stored glycogen in liver cells; and then converting it back into glucose when the the body needs it for energy;
• production of blood clotting factors;
• production of amino acids (the building blocks for making proteins), including those used to help fight infection;
• the processing and storage of iron necessary for red blood cell production;
• manufacture of cholesterol and other chemicals required for fat transport;
• conversion of waste products of body metabolism into urea that is excreted in the urine; and
• metabolizating medications into their active ingredient in the body.

Cirrhosis is a term that describes permanent scarring of the liver. In cirrhosis, the normal liver cells are replaced by scar tissue that cannot perform any liver function.

Acute liver failure may or may not be reversible, meaning that on occasion, there is a treatable cause and the liver may be able to recover and resume its normal functions.