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 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: Cirrhosis is a term that describes permanent scarring of the liver. 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 is there is a treatable cause and the liver is able to recover and resume its normal functions. The liver can be damaged in a variety of ways. Alcohol abuse Alcohol abuse is the most common cause of liver disease in North America. Alcohol is directly toxic to liver cells and can cause liver inflammation, referred to as alcoholic hepatitis. In chronic alcohol abuse, fatty accumulation (steatosis) occurs in liver cells causing the cells to malfunction. Cirrhosis Cirrhosis is a late-stage liver disease. Scarring of the liver and loss of functioning liver cells cause the liver to fail. Drug-induced liver disease Liver cells may become temporarily inflamed or permanently damaged by exposure to medications or drugs. Some medications or drugs require an overdose to cause liver injury while others may cause the damage even when taken in the appropriately prescribed dosage. Taking excess amounts of acetaminophen (Tylenol, Panadol) can cause liver failure that is permanent. This is the reason that warning labels exist on many over-the-counter medications that contain acetaminophen and why prescription narcotic-acetaminophen combination medications (for example, Vicodin, Lortab, Norco, Tylenol #3) limit the numbers of tablets to be taken in a day. Statin medications are commonly prescribed to control elevated blood levels of cholesterol. Even when taken in the appropriately prescribed dose, liver inflammation may occur and can be detected by blood tests that measure liver enzymes. Stopping the medication usually results in return of the liver function to normal. Niacin is another medication used to control elevated blood levels of cholesterol, but liver inflammation for this medication is related to the dose taken. Similarly, patients with underlying liver disease may be at higher risk of developing liver disease due medications such as niacin. There are numerous other medications that may cause liver inflammation, most of which will resolve when the medication is stopped. These include antibiotics such asnitrofurantoin (Macrodantin, Furadantin, Macrobid), amoxicillin and clavulanic acid(Augmentin, Augmentin XR), tetracycline (Sumycin), and isoniazid (INH, Nydrazid, Laniazid). Methotrexate (Rheumatrex, Trexall), a drug used to treat autoimmune disorders and cancers, has a variety of side effects including liver inflammation that can lead to cirrhosis. Disulfiram (Antabuse) used to treat alcoholics and can cause liver inflammation. Some herbal remedies and excessive amounts of vitamins can cause hepatitis, cirrhosis and liver failure. Examples include vitamin A, kava kava, ma-huang, andcomfrey. Many mushrooms are poisonous to the liver and eating unidentified mushrooms gathered in the woods can be lethal. Infectious hepatitis 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 andliver 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 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 astoxoplasmosis 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. Hemochromatosis Hemachromatosis (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. Hemachromatosis is an inherited disease. Wilson's Disease Wilson's disease is another inherited disease that affects the body's ability to metabolize copper. Wilson's disease may lead to cirrhosis and liver failure. Gilbert's Disease 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. Cancers 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 andHodgkin'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, andpregnancy. 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 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. 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. Other diseases and conditions Conditions such as portal hypertension (increased blood pressure within the portal vein), abnormal blood clotting, and hepatic encephalopathy (abnormal brain function due to elevated levels of ammonia in the blood stream). Classic symptoms of liver disease include: Fatigue, weakness and weight loss may also be occur. However, since there are a variety of liver diseases, the symptoms tend to be specific for that illness until late-stage liver disease and liver failure occurs. Examples of liver disease symptoms due to certain conditions or diseases include: Additionally, there is increased pressure within the cirrhotic liver affecting blood flow through the liver. Increased pressure in the portal vein causes blood flow to the liver to slow and blood vessels to swell. Swollen veins (varices) form around the stomach and esophagus and are at risk for bleeding. Often, the onset of a liver disease is gradual and there is no specific symptom that brings the affected individual to seek medical care. Fatigue, weakness and weight loss that cannot be explained should prompt a visit for medical evaluation. Jaundice or yellow skin is never normal and should prompt an evaluation by a medical professional. Persisting fever, vomiting, and abdominal pain should also prompt medical evaluation as soon as possible. The precise diagnosis of liver disease involves a history and physical examination performed by the health care professional. Understanding the symptoms and the patient's risk factors for liver disease will help guide any diagnostic tests that may be considered. Liver disease can have physical findings in almost all body systems including the heart, lungs, abdomen, skin, cognitive function, and other parts of the nervous system. The physical examination can require evaluation of the entire body. Blood tests are helpful in assessing liver inflammation and function. Specific liver function blood tests include: Other blood tests may be considered, including the following: Imaging studies may be used to visualize, not only the liver, but other organs nearby that may be diseased. Examples of imaging studies include: Liver biopsy may be considered to confirm a specific diagnosis for liver disease. Under local anesthetic, a long thin needle is inserted through the chest wall into the liver, where a small sample of liver tissue is obtained for examination under a microscope. The outlook and outcome for a patient depends upon the underlying diagnosis. Interestingly, in patients with cirrhosis, there may be little correlation between the amount of damage found on liver biopsy and the ultimate outcome. A patient may never develop symptoms and have a normal life-span or may develop significant symptoms.What is liver disease?
What are the causes of liver disease?
What are the risk factors for liver disease?
What are the symptoms of liver disease?
When to seek medical care for liver disease
How is liver disease diagnosed?
Can liver disease be prevented?
What is the outlook for a patient with liver disease?
Liver Disease At A Glance
Sunday, April 18, 2010
Labels: Liver Disease (Hepatic Disease)
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