• Also Known As:
  • Hepatic Disease
Medically Reviewed by Expert Board

This page was fact checked by our expert Medical Review Board for accuracy and objectivity. Read more about our editorial policy and review process.

This article was last modified on
Learn more about...

What is the liver and what is liver disease?

The liver is a vital organ located in the upper right-hand side of the abdomen. It is as large as a football, weighs 2-3 pounds, and performs numerous functions for the body, including:

  • Metabolizing and detoxifying substances that would otherwise be harmful to the body
  • Converting nutrients derived from food into essential blood components
  • Regulating blood clotting
  • Producing proteins and enzymes
  • Maintaining hormone balances
  • Storing some vitamins
  • Making factors that help the immune system fight infection
  • Removing bacteria from the blood
  • Making bile, which is essential for digestion

Bile, a greenish-yellow fluid consisting of bile acids or salts and waste products such as bilirubin (which comes from breakdown of old red blood cells) and other bile pigments, flows through small bile ducts inside the liver. The bile moves from these small ducts into larger ones, like streams into a river, eventually converging into the common bile duct and exiting the liver. Some of the bile flows directly to the duodenum; the rest is stored and concentrated in the gallbladder. After a person eats, the gallbladder, a fist-sized organ that sits next to the liver, releases some of the stored bile into the small intestine, where it helps to digest fats.

Liver disease is any condition that causes liver inflammation or damage and may affect liver function. It is categorized both by the cause and the effect it has on the liver. Causes may include infection, injury, exposure to drugs or toxic compounds, an autoimmune process, or a genetic defect that leads to the depositing and build-up of damaging substances, such as iron or copper. Effects of these injuries to the liver may include inflammation, scarring, obstructions, blood clotting abnormalities, and liver failure.

About Liver Disease

Signs and Symptoms

Liver disease may not cause any symptoms at first or the symptoms may be nonspecific, like weakness and loss of energy.

In acute liver disease, the most common signs and symptoms include:

  • Those related to problems processing bilirubin, such as yellow skin and eyes (jaundice), dark urine, and light stools
  • loss of appetite
  • Nausea
  • Vomiting
  • Diarrhea

Chronic liver disease symptoms may also include jaundice, dark urine, and light stools but also can produce signs and symptoms such as:

  • Abdominal swelling (due to ascites)
  • Itching (pruritus)
  • Unexplained weight loss or gain
  • Abdominal pain

These symptoms usually do not develop until the disease has reached an advanced stage.


General Laboratory Tests
The goals of testing for liver disease are to screen for and detect liver injury, to evaluate its severity, diagnose the cause, and to monitor liver status over time.

  • Screening and early detection are important since significant liver damage may occur with few or no symptoms.
  • Diagnosing the cause helps healthcare practitioners understand what type of liver disease you have and how to treat it. The liver is often capable of repairing injuries and resolving inflammation, but conditions that cause obstruction of the bile ducts and/or lead to cirrhosis can cause permanent, progressive liver damage.
  • Monitoring the status of your liver over time allows steps to be taken to preserve liver function.

General lab tests measure the levels of specific enzymes, bilirubin, and protein that may be abnormal when liver injury is present.

  • A comprehensive metabolic panel (CMP) is a group of tests that is often done as part of general health screening. It includes several tests that help evaluate liver function.
  • A liver panel includes the same liver tests as the CMP and may be ordered when you have signs and symptoms that may be due to liver injury or when you are at risk for developing liver disease.

If any of the liver tests are abnormal, then they indicate the need for additional evaluation. A healthcare practitioner will order diagnostic testing for whatever liver condition(s) a patient is suspected to have (see Select Tests below). Tests included in these panels may also be ordered individually to monitor a person with a liver disease:

  • Alanine aminotransferase (ALT) – an enzyme found mainly in the liver; best test to detect hepatitis
  • Alkaline phosphatase (ALP) – an enzyme related to the bile ducts; often increased if ducts are blocked
  • Aspartate aminotransferase (AST) – an enzyme found in the liver and a few other places, particularly the heart and other muscles
  • Gamma-glutamyl transferase (GGT) – an enzyme found mainly in the liver; very sensitive to changes in liver status, especially when bile ducts are blocked
  • Total bilirubin – measures all of the bilirubin in the blood; levels are increased with many liver diseases and other conditions, such as hemolysis, that lead to increased production of bilirubin
  • Direct bilirubin – measures a form of bilirubin that is conjugated (combined with another compound) in the liver; only increased in liver disease
  • Albumin – measures albumin, the main protein made by the liver, and tells how well the liver is making it
  • Total protein – measures albumin and all other proteins in blood, including antibodies present to help fight off infections (antibodies are not made in the liver)
  • Lactate dehydrogenase (LD or LDH) – an enzyme released with tissue damage; may be elevated with acute liver disease

Select Tests
One or more select tests may be ordered to help diagnose the cause of liver dysfunction. Some may be used to monitor disease status and/or effectiveness of treatment. Some examples include:

For more information on laboratory tests used for specific types of liver diseases, see the section on Types of Liver Disease below.

Non-laboratory tests may include:

  • Ultrasound
  • CT (computed tomography) scan
  • MRI (magnetic resonance imaging)
  • MRCP (magnetic resonance cholangiopancreatography)
  • PTC (percutaneous transhepatic cholangiogram)
  • ERCP (endoscopic retrograde cholangiopancreatography)

For more information on these imaging procedures, see RadiologyInfo.org.


The most important treatment for liver disease is prevention. Vaccines are available for hepatitis A and B, and many cases of hepatitis can be prevented by avoiding the risk factors that spread the hepatitis viruses.

Although liver inflammation due to hepatitis or other causes may resolve over time, liver damage may also become permanent. Steps to treat liver disease include protecting and supporting remaining liver function, minimizing further damage and complications, and addressing the underlying cause of the damage. Treatment may range from taking specific medications, to surgery, to – in severe cases – liver transplantation.

People who are diagnosed with liver disease will often require long-term monitoring and should talk to their healthcare providers to determine the best treatment options for their condition.

Types of Liver Disease

Acute liver failure

Acute liver failure (ALF) is a rapid decrease in liver function. ALF can cause accumulation of fluid (edema) in the brain, deterioration of the brain, abnormal bleeding, and multiple organ failure that is often fatal. The most common cause of ALF in the U.S. is liver damage due to drugs, such as an acetaminophen overdose, with use of prescription, illicit, and herbal drugs, or with the ingestion of poisonous mushrooms or organic solvents. ALF is also sometimes seen with viral or autoimmune hepatitis, nonalcoholic fatty liver disease (see Hepatitis), fatty liver that occurs during pregnancyWilson disease, and with the rapid worsening of other liver diseases.


Imaging scans

  • Ultrasound
  • CT (computed tomography)
  • MRI (magnetic resonance imaging)

For more information on these imaging procedures, see RadiologyInfo.org.

Alcoholic liver disease

The liver is responsible for the metabolism of alcohol. It breaks it down so that it can then be eliminated from the body. Alcohol can damage or destroy liver cells, and the liver can be seriously injured when more alcohol is consumed than it can process. Excessive consumption of alcohol is a common cause of liver damage, and alcoholic liver disease can occur after years of heavy drinking. It can lead to:

  • Fatty liver disease – this is the excessive accumulation of fat in liver cells. This condition usually produces no symptoms or mild symptoms and occurs in the earliest stages of liver disease. It will typically go away when a person stops drinking.
  • Alcoholic hepatitis – this is inflammation and swelling of the liver. It may be chronic yet mild, lasting for years but with no specific symptoms. With mild cases, the damage may be reversed if alcohol consumption is stopped. If it continues, over time, the liver may sustain more and more damage. If the damage becomes severe, the symptoms can appear quickly, within hours or days, and may be fatal.
  • Cirrhosis – this is scarring of the liver and the most serious form of alcoholic liver disease. It occurs when healthy liver tissue is replaced by hard scar tissue, affecting the structure of the liver and affecting its ability to function. The damage commonly cannot be reversed but may not progress further if a person stops drinking. Cirrhosis can lead to liver failure and increases the risk of liver cancer.

Alcoholic liver disease is not typically tested for directly with laboratory tests. The diagnosis is often arrived at by examining the patient and getting a full medical history, especially about  alcohol consumption. There are some tests that may be performed to help evaluate someone with liver disease due to chronic alcohol use, and certain tests may help detect chronic and/or relapse in alcohol drinking in those who deny it.

Testing may include:

  • Gamma-glutamyl transferase (GGT) – a liver enzyme that is increased by heavy alcohol intake and also by many other conditions that affect the liver
  • Liver panel – used to detect and/or determine the extent of liver damage
  • Ethanol level – if alcohol is suspected to be a cause of liver disease (remains elevated for only a few hours after last drinking, however)
  • Carbohydrate-deficient transferrin (CDT) – can indicate relapse to heavy drinking following a period of abstinence but may be less sensitive for women and younger people

There is no specific treatment for alcoholic liver disease. Usually, the first step is to stop drinking alcohol, along with avoiding other substances that can harm the liver. Many people fully recover from this type of liver disease if this is done soon enough, although it may take months for the liver to heal. Participating in a rehabilitation program or counseling may be helpful in abstaining from alcohol or treating an alcohol addiction (alcoholism). Occasionally, there is lasting damage such as cirrhosis and even liver failure. If the liver is irreversibly damaged, then a liver transplant may be an option. Transplant programs usually require someone with a history of alcohol abuse (even if alcohol may not be the underlying cause) to successfully complete a rehabilitation program before transplant can be considered as an option.

Autoimmune liver disease

Autoimmune disorders arise when the immune system produces a response against one or more of the body’s normal constituents as if they are harmful. When the immune system fails to distinguish between “self” and “non-self”, it may produce immune cells or antibodies (called autoantibodies) that target its own cells, tissues, and/or organs. Those attacks cause inflammation and tissue damage that lead to autoimmune disorders. Sometimes these conditions can affect the liver.

Autoimmune hepatitis – although the cause is not fully understood, the immune system attacks the liver and can damage it over time. Learn more about autoimmune hepatitis and associated tests in the Hepatitis article.

Primary biliary cholangitis
Primary biliary cholangitis (PBC) is a chronic disease that inflames and destroys small bile ducts in the liver, impedes the flow of bile, and damages liver tissue. It is a progressive disorder that affects more women than men. The exact cause of PBC is not known, but it is thought to be an autoimmune process.

Learn more about PBC at MayoClinic.com.


Primary sclerosing cholangitis
Primary sclerosing cholangitis (PSC) is a chronic disease that is usually associated with inflammatory bowel disease. PSC involves the inflammation, scarring, and destruction of bile ducts, mostly those outside the liver, impedance of bile flow, and damage to liver tissue. The exact cause of PSC is not known, but it is thought to be an autoimmune process. The disorder is more common in men than women.

Learn more about PSC at the National Institute of Diabetes and Digestive and Kidney Diseases web site.


  • Liver biopsy

Imaging scans

  • Ultrasound
  • Magnetic resonance cholangiopancreatography (MRCP)
  • Percutaneous transhepatic cholangiogram (PTC)
  • ERCP (endoscopic retrograde cholangiopancreatography)

For more information on these imaging procedures, see RadiologyInfo.org.

Budd-Chiari syndrome

Budd-Chiari syndrome is a group of symptoms that occur when one or more blood clots narrow or block the hepatic veins, those that carry blood out of the liver. This can damage the liver and the blood vessels that support it. It causes blood to accumulate in the liver, enlarging it and increasing pressure in the vein that carries blood from the digestive organs and spleen into the liver – the portal vein. This in turn can lead to fluid accumulation (edema), especially in the abdomen (ascites), dilated veins in the esophagus (varices) and abdomen, esophageal bleeding, and liver cirrhosis.

Budd-Chiari syndrome may occur in those who have a condition that increases the risk of blood clots, such as:

Symptoms may emerge slowly and worsen over time or develop abruptly, such as is sometimes seen as a complication of pregnancy.


Imaging scans

  • MRI (magnetic resonance imaging)
  • Ultrasound
  • CT (computed tomography)

For more information on these imaging procedures, see RadiologyInfo.org.


Cirrhosis is a chronic liver disease that causes advanced scarring of liver tissue. The liver can repair many injuries, but cirrhosis is commonly irreversible. While it may be caused by any condition that affects the liver, in the U.S. it is commonly associated with viral hepatitis and alcoholism. Other significant causes of cirrhosis include nonalcoholic steatohepatitis, a form of nonalcoholic fatty liver disease (see Hepatitis article), associated with the accumulation of fat in the liver, which public health officials speculate may be linked to rising rates of obesity in the U.S.

Cirrhosis can cause decreased liver function, chronic liver failure, easy bruising and bleeding, muscle wasting, fluid buildup in the abdomen (ascites), increased blood pressure in the vein that carries blood from the digestive organs to the liver (portal hypertension), and a number of other problems. Some people may experience severe symptoms and complications while others, with similar liver damage, will have few to moderate symptoms. Cirrhosis increases the risk of developing liver cancer.


  • Liver biopsy

For a complete list of tests, see the article on Cirrhosis.

Genetic liver diseases

Genetic mutations can lead to conditions that affect the liver. These are relatively rare diseases, two of which involve the excess buildup of minerals in the body.

  • Hemochromatosis – an iron metabolism disorder that leads to excessive buildup of iron in tissues and organs. It may be genetic (inherited) or acquired and can cause organ failure, particularly of the liver, heart, and pancreas. For more information, see the article on Hemochromatosis.
  • Wilson disease – a copper metabolism disorder that leads to excessive buildup of copper in tissues and organs. It results from an inherited genetic mutation and can cause liver, brain, and kidney damage. For more information, see the article on Wilson Disease.

Alpha-1 antitrypsin deficiency
Alpha-1 antitrypsin (AAT) is a protein that helps protect the lungs. It is produced in the liver at the direction of two copies of a protease inhibitor (SERPINA1) gene. If there is a mutation (variant) in one or both of the gene copies, then less AAT and/or dysfunctional AAT is produced. If AAT production is 30% of normal or less, then an affected person will experience alpha-1 antitrypsin deficiency and have an increased risk of developing emphysema. When AAT is dysfunctional, it tends to accumulate in the liver, forming abnormal protein chains and damaging the liver. About 10% of newborns affected with AAT deficiency have jaundice. AAT deficiency is currently the most common genetic cause of liver disease in children.



Hepatitis is an inflammation of the liver that is most frequently due to viral infections, although it can also have other causes, such as exposure to chemicals, over-the-counter or prescription drugs, heavy alcohol use, inherited diseases, autoimmune disease, or fatty buildup in the liver.

Hepatitis can be acute, flaring up and then resolving within a few weeks to months, or chronic, enduring over many years. Chronic hepatitis may persist for 20 years or more before causing significant symptoms related to progressive liver damage, such as cirrhosis and liver cancer, and can cause death.

Find more information about the various types and related tests in the article on Hepatitis.


Viral hepatitis
Liver inflammation caused by an infection with one of the five hepatitis viruses: A, B, C, D, or E. Acute hepatitis is commonly associated with the A, B, and E viruses while chronic hepatitis is only caused by B, C and D.

Tests for common hepatitis viruses include:

Parasitic infection
Relatively rare in the U.S., a variety of parasites can migrate to the liver and cause tissue damage and blockages. Examples include:

  • Malaria, which can actively reproduce in liver cells, then go through a period of dormancy before causing periodic disease relapses
  • Some parasitic worms, such as Ascaris lumbricoides and Chinese liver flukes (i.e., Clonorchis sinensis and Opisthorchis viverrini), can block bile ducts.
  • Schistosoma species (parasitic worms) can cause schistosomiasis and progressive liver scarring.
  • Echinococcus granulosus forms cysts in the liver.


Imaging scans

  • Ultrasound
  • X-ray
  • CT (computed tomography)
  • MRI (magnetic resonance imaging)

For more information on these imaging procedures, see RadiologyInfo.org.

Liver cancer

Liver cancer is the uncontrolled growth of cells within the liver. Cancer that originates in one part of the body but then spreads to the liver is not strictly known as “liver cancer” but rather keeps the name of its origin. For example, metastatic breast or lung cancer is still considered “breast” or “lung” cancer—and is treated accordingly—even if it spreads to the liver, because it originated in the breast or lung.

  • The most common form of liver cancer in the U.S. is hepatocellular carcinoma (HCC), cancer that arises from liver cells called hepatocytes. According to the American Cancer Society, this type accounts for about 3 out of 4 cases of primary liver cancer.
  • Another 1-2 cases out of 10 are cancers that start in the bile ducts (cholangiocarcinomas).

Liver cancer is frequently asymptomatic at first, so it is not usually diagnosed in its earliest stages. Those with chronic hepatitis B and those with cirrhosis are at an increased risk of developing liver cancer. Many people with cirrhosis or advanced chronic hepatitis are regularly screened for liver cancer to detect it early, when it may be more treatable.


  • AFP (alpha-fetoprotein) – if you have been diagnosed with HCC, an AFP test may be ordered periodically to help monitor your response to therapy and to monitor for cancer recurrence. Though the test is often ordered to monitor people with chronic liver diseases such as cirrhosis, chronic hepatitis B or hepatitis C because they have an increased lifetime risk of developing liver cancer, most current guidelines do not recommend this use.
  • DCP (Des-gamma-carboxy prothrombin) – may be used along with other tumor markers such as an AFP to monitor the effectiveness of treatment for HCC and monitor for recurrence of HCC after successful treatment
  • Liver biopsy – to diagnose liver cancer

Imaging scans

  • Ultrasound
  • CT (computed tomography)
  • MRI (magnetic resonance imaging)
  • Angiography

For more information on these imaging procedures, see RadiologyInfo.org.

Obstruction of bile ducts

Gallstones, tumors, trauma, cysts, and inflammation can cause blockages or obstructions in the bile ducts. When this is severe, bile and its associated wastes accumulate in the liver, causing jaundice, dark brown urine, and pale-colored stools. The affected person may not have any symptoms initially, but if the condition persists or worsens, it can cause liver and gallbladder damage.

If the duct that drains bile from the gallbladder is blocked, it can cause sharp pain to develop suddenly in the upper right part of the abdomen and may lead to fever and gallbladder infection.


Imaging scans

  • Ultrasound
  • CT (computed tomography)
  • Magnetic resonance cholangiopancreatography (MRCP)
  • Percutaneous transhepatic cholangiogram (PTC)
  • ERCP (endoscopic retrograde cholangiopancreatography)

For more information on these imaging procedures, see RadiologyInfo.org.

View Sources

Sources Used in Current Review

Alcohol Research Current Reviews. 2017. Alcoholic Liver Disease: Pathogenesis and Current Management. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5513682/. Accessed 6/23/2019.

American Cancer Society. (April 1, 2019). What is Liver Cancer? Available online at https://www.cancer.org/cancer/liver-cancer/about/what-is-liver-cancer.html. Accessed 6/23/2019.

Best Practice & Research Clinical Gastroenterology. 2012. Recent developments in acute liver failure. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3551290/. Accessed 6/23/2019.

Gastroenterology. 2014. Pathological Features of Fatty Liver Disease. Available online at https://www.gastrojournal.org/article/S0016-5085(14)00981-0/fulltext. Accessed 6/23/2019.

Genetics Home Reference. 2014. Wilson Disease. Available online at https://ghr.nlm.nih.gov/condition/wilson-disease. Accessed 6/23/2019.

Healthline. 2017. Liver Function Tests. Available online at https://www.healthline.com/health/liver-function-tests. Accessed 6/23/2019.

Journal of Clinical and Translational Hepatology. 2014. Primary Biliary Cirrhosis and Primary Sclerosing Cholangitis: a Review Featuring a Women’s Health Perspective. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4521232/. Accessed 6/23/2019.

Korean Journal of Radiology. 2011. Liver Flukes: the Malady Neglected. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3088844/. Accessed 6/23/2019.

Medscape. 2017. Budd-Chiari Syndrome. Available online at https://emedicine.medscape.com/article/184430-overview. Accessed 6/23/2019.

Medscape. 2017. Primary Sclerosing Cholangitis (PSC). Available online at https://emedicine.medscape.com/article/187724-overview. Accessed 6/23/2019.

MedlinePlus. 2018. Liver Function Tests. Available online at https://medlineplus.gov/liverfunctiontests.html. Accessed 6/23/2019.

Radiological Society of America. 2017. Cirrhosis of the liver. Available online at https://www.radiologyinfo.org/en/info.cfm?pg=cirrhosisliver. Accessed 6/27/2019.

U.S. Department of Health and Human Resources. National Institute of Diabetes and Digestive and Kidney Diseases. 2017. Diagnosis of Biliary Atresia. Available online at https://www.niddk.nih.gov/health-information/liver-disease/biliary-atresia/diagnosis. Accessed 6/23/2019.

U.S. Department of Health and Human Resources. National Institute of Diabetes and Digestive and Kidney Diseases. 2018. Definition and Facts for Cirrhosis. Available online at https://www.niddk.nih.gov/health-information/liver-disease/cirrhosis/definition-facts. Accessed 6/23/2019.

U.S. Department of Health and Human Resources. National Institute of Diabetes and Digestive and Kidney Disease. 2016. Endoscopic Retrograde Cholangiopancreatography (ERCP). Available online at https://www.niddk.nih.gov/health-information/diagnostic-tests/endoscopic-retrograde-cholangiopancreatography. Accessed 6/26/2019.

U.S. Department of Health and Human Resources. National Institute of Diabetes and Digestive and Kidney Diseases. 2017. What is viral hepatitis? Available online at https://www.niddk.nih.gov/health-information/liver-disease/viral-hepatitis/what-is-viral-hepatitis. Accessed 6/23/2019.

Sources Used in Previous Reviews

Thomas, Clayton L., Editor (1997). Taber’s Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].

Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby’s Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.

ALF (2001). Your Liver, A Vital Organ. American Liver Foundation [On-line information]. Available online through http://www.liverfoundation.org.

Worman, H., (2001, August 23). Diseases of the Liver. Columbia University. Available online at http://cpmcnet.columbia.edu/dept/gi/disliv.html.

Bacon, B., Hemochromatosis. Carey, W., & Melnyk, C., Viral Liver Disease. Hacker, J., et. al., Alcoholic Liver Disease. American College of Gastroenterology [On-line patient Information]. Available online at http://www.acg.gi.org/acg-dev/patientinfo/frame_giproblems.html.

MedicineNet.com: Liver Overview. Available online at http://www.focusonliver.com/script/main/hp.asp.

Vierling, J. (2001 August 21 last editorial review) Primary Biliary Cirrhosis (PBC), part 1. MedicineNet.com [On-line information]. Available online at http://www.focusondigestion.com/script/main/Art.asp?li=MNI&ArticleKey=1934&page=2.

(1999 March 12 Last Editorial Review). Primary Sclerosing Cholangitis. MedicineNet.com [On-line information]. Available online at http://www.focusondigestion.com/script/main/art.asp?articlekey=8572&rd=1.

(2006 January 19, Reviewed). Viral Hepatitis A Fact Sheet. CDC, National Center for Infectious Diseases [On-line information]. Available online at http://www.cdc.gov/ncidod/diseases/hepatitis/a/fact.htm.

(2006 January 19, Reviewed). Hepatitis B Frequently Asked Questions. National Center for Infectious Diseases [On-line information]. Available online at http://www.cdc.gov/ncidod/diseases/hepatitis/b/faqb.htm.

(© 2002-2003) What are the Diseases that Affect the Liver? American Liver Foundation [On-line information]. Available online through http://www.liverfoundation.org.

(2006 February 9, Revised) American Cancer Society, What is Liver Cancer. American Cancer Society [On-line information]. Available online through http://www.cancer.org.

(2006 January 25, Updated). NINDS Reye’s Syndrome Information Page. National Institute of Neurological Disorders and Stroke [On-line information]. Available online at http://www.ninds.nih.gov/disorders/reyes_syndrome/reyes_syndrome.htm.

(2006 January 25, Updated). NINDS Wilson’s Disease Information Page. National Institute of Neurological Disorders and Stroke [On-line information]. Available online at http://www.ninds.nih.gov/disorders/wilsons/wilsons.htm.

(2005 August, Reviewed). Cirrhosis and Portal Hypertension. Familydoctor.org [On-line information]. Available online at http://familydoctor.org/188.xml.

(2005 January 3). NIH Action Plan Charts Future Challenges for Liver Disease Research. National Institute of Diabetes & Digestive & Kidney Diseases [On-line press release]. Available online at http://www.niddk.nih.gov/welcome/releases/01-03-05.htm.

(Updated 2007 September 28). The Progression of Liver Disease. American Liver Foundation [On-line information]. Available online at http://www.liverfoundation.org/education/info/progression/. Accessed December 2009.

Mayo Clinic Staff (2009 April 18). Liver Problems. MayoClinic.com [On-line information]. Available online at http://www.mayoclinic.com/health/liver-problems/DS01133/METHOD=print. Accessed December 2009.

Herrine, S. (Revised 2009 July). Approach to the Patient with Liver Disease, Introduction. Merck Manual for Healthcare Professionals [On-line information]. Available online at http://www.merck.com/mmpe/sec03/ch022/ch022a.html. Accessed December 2009.

Calvaruso, V. and Craxi, A. (2009 October 22). Implication of Normal Liver Enzymes in Liver Disease. Medscape from J Viral Hepat. 2009;16(8):529-536. [On-line information]. Available online at http://www.medscape.com/viewarticle/709156. Accessed December 2009.

Wolf, D. (Updated 2009 December 15). Cirrhosis. Medscape [On-line information]. Available online at http://emedicine.medscape.com/article/185856-overview. Accessed December 2009.

Pyrsopoulos, N. and Reddy, K. R. (Updated 2008 September 22). Primary Biliary Cirrhosis. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/171117-overview. Accessed December 2009.

Bonheur, J. and Ells, P. (Updated 2009 August 29). Biliary Obstruction. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/187001-overview. Accessed December 2009.

Grenache, D. et. al. (Updated 2009 November). Liver Disease Evaluation. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/LiverDzEval.html. Accessed December 2009.

Pagana, K. D. & Pagana, T. J. (© 2007). Mosby’s Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 606-609.

Clarke, W. and Dufour, D. R., Editors (© 2006). Contemporary Practice in Clinical Chemistry: AACC Press, Washington, DC. Pp 269-279.

Kasper DL, Braunwald E, Fauci AS, Hauser SL, Longo DL, Jameson JL eds, (2005). Harrison’s Principles of Internal Medicine, 16th Edition, McGraw Hill, Pp 1808-1813.

Henry’s Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2007, Pp 265, 267, 274-276.

Liver Disorders. CHealth. Available online at http://chealth.canoe.ca/condition_info_details.asp?disease_id=176. Accessed November 2013.

Nonalcoholic Fatty Liver Disease. (Feb. 19, 2011.) Mayo Clinic. Available online at http://www.mayoclinic.com/health/nonalcoholic-fatty-liver-disease/DS00577/DSECTION=tests-and-diagnosis. Accessed November 2013.

Chronic Liver Disease / Cirrhosis. Johns Hopkins Medicine Health Library. Available online through http://www.hopkinsmedicine.org. Accessed November 2013.

Cirrhosis. (Updated Oct. 23, 2013.) MedicineNet.com. Available online at http://www.medicinenet.com/cirrhosis/page3.htm#what_are_the_common_causes_of_cirrhosis. Accessed November 2013.

(Update October 4, 2011) American Liver Foundation. Alcohol Related Liver Disease. Available online at http://www.liverfoundation.org/abouttheliver/info/alcohol/. Accessed December 2013.

(Update: Nov 16, 2012) Longstreth G. Alcoholic Liver Disease. MedlinePlus Medical Encyclopedia. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000281.htm. Accessed December 2013.