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 that may occur to 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 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 digestion of food.
The term “hepatitis” means inflammation, and liver cells can become inflamed because of infection.
Hepatitis A is a viral infection that is caused primarily through the fecal-oral route when small amounts of infected fecal matter are inadvertently ingested. Hepatitis A causes an acute inflammation of the liver which generally resolves spontaneously. The hepatitis A vaccine can prevent this infection.
Hepatitis B is spread by exposure to body fluids (needles from drug abusers, contaminated blood, and sexual contact) and can cause an acute infection, but can also progress to cause chronic inflammation (chronic hepatitis) that can lead to cirrhosis and liver cancer. The hepatitis B vaccine prevents this infection.
Hepatitis C causes chronic hepatitis. An infected individual may not recall any acute illness. Hepatitis C is spread by exposure to body fluids (needles from drug abusers, contaminated blood, and sexual contact). Chronic hepatitis C may lead to cirrhosis and liver cancer. At present, there is no vaccine against this virus.
Hepatitis D is a virus that requires concomitant infection with hepatitis B to survive, and is spread via body fluid exposure (needles from drug abusers, contaminated blood, and sexual contact).
Hepatitis E is a virus that is spread via contaminated food and water exposure.
Other viruses can also cause liver inflammation or hepatitis as part of the cluster of symptoms. Viral infections with infectious mononucleosis (Epstein Barr virus), adenovirus, and cytomegalovirus can inflame the liver. Non-viral infections such as toxoplasmosis and Rocky Mountain spotted fever are less common causes.
Non-Alcoholic fatty liver disease
- Accumulation of fat within the liver can cause gradual decrease in liver function. Also known as nonalcoholic steatohepatitis, fatty liver disease, or NASH. Eating too many fatty foods such as meats and oils can cause you to develop liver disease as a result of a buildup of unprocessed fats in your liver.
haemochromatosi (iron overload) is a metabolic disorder that leads to abnormally elevated iron stores in the body. The excess iron may be found in the tissues of the liver, pancreas, and heart and can lead to inflammation, cirrhosis, liver cancer, and liver failure. haemochromatosis is an inherited disease. It is the most common genetic liver disorder. It involves excess iron storage and is usually diagnosed in adults. There are numerous genetic liver diseases that affect children. Most of the diseases involve a defective element that results in liver injury (such as biliary atresia, where the bile ducts are absent or too small) or a missing enzyme or protein that leads to damaging deposits in the liver (such as galactosaemia, the absence of a milk sugar enzyme, which leads to milk sugar accumulation; and Wilson’s disease, where copper builds up in the liver).
Anything that causes severe ongoing injury to the liver can lead to cirrhosis. It is marked by cell death and scar formation and is a progressive disease that creates irreversible damage. Cirrhosis is treated by trying to limit further damage; if it is caused by a virus or another treatable cause of liver injury, treating the cause can stabilize the disease and prevent deterioration in liver function. Cirrhosis has no signs or symptoms in its early stages, but as it progresses, it can cause fluid build-up in the abdomen (called ascites), muscle wasting, bleeding from the intestines, easy bruising, enlargement of the breasts in men (called gynaecomastia), and a number of other problems. Liver function is monitored with such tests as albumin, prothrombin time, bilirubin, and liver function tests. In extreme cases, liver transplantation may be needed.
In Gilbert’s disease, there is an abnormality in bilirubin metabolism in the liver. It is a common disease that affects up to 7% of the North American population. There are no symptoms and it is usually diagnosed incidentally when an elevated bilirubin level is found on routine blood tests. Gilbert’s disease is a benign condition and no treatment is necessary.
Primary cancers of the liver arise from liver structures and cells. Two examples include hepatocellular carcinoma and cholangiocarcinoma.
Metastatic cancer (secondary cancer of the liver) begins in another organ and spreads to the liver, usually through the blood stream. Common cancers that spread to the liver begin in the lung, breast, large intestine, stomach, and pancreas. Leukemia and Hodgkin’s lymphoma may also involve the liver.
Blood flow abnormalities
Budd Chiari syndrome is a disease in which blood clots form in the hepatic vein and prevent blood from leaving the liver. This can increase portal vein pressure and lead to cirrhosis and liver failure. Causes of Budd Chiari syndrome include polycythemia (elevated red blood cell count), inflammatory bowel diseases, sickle-cell disease, and pregnancy.
Congestive heart failure, where fluid and blood backs up in the large veins of the body can cause liver swelling and inflammation.
Bile flow abnormalities or bile duct disorders
Normally, bile flows from the liver into the gallbladder and ultimately into the intestine to help with the digestion of food. If bile flow is obstructed, it can cause inflammation within the liver. Most commonly, gallstones can cause an obstruction of the ducts that drains bile from the liver. Medical conditions such as primary sclerosing cholangitis and primary biliary cirrhosis can damage or destroy your bile ducts and cause liver disease.
Abnormalities of the opening of the bile duct into the intestine (sphincter of Oddi) can lead to abnormalities of bile flow. The sphincter of Oddi acts as a “valve” that allows bile to flow from the common bile duct into the intestine.
Primary biliary cirrhosis and primary sclerosing cholangitis can lead to progressive scarring of the bile ducts, causing them to become narrow, which results in reduced bile flow through the liver. Eventually, damage and scarring of the liver architecture causes liver failure to develop. When an obstruction occurs, bile and its associated wastes accumulate in the blood and the patient’s skin and eyes often turn yellow (jaundice); bilirubin in the urine turns it a dark brown color, while lack of bilirubin in the intestines causes the stool to become very pale coloured. Blood tests may show elevated levels of bilirubin, alkaline phosphatase (ALP), and liver enzymes.
- Diagnosing Hepatitis: Tools and Tests (everydayhealth.com)
- Managing Hepatitis Liver Damage (everydayhealth.com)
- What Every Pregnant Woman Should Know About Hepatitis B (everydayhealth.com)
- Questions to Ask Your Doctor About Hepatitis (everydayhealth.com)