1. Hepatitis Slideshow Pictures
2. Take the Alcohol Quiz
3. Alcohol Abuse Slideshow Pictures

Medical Author:

Siamak T. Nabili, MD, MPH

Siamak T. Nabili, MD, MPH

Dr. Nabili received his undergraduate degree from the University of California, San Diego (UCSD), majoring in chemistry and biochemistry. He then completed his graduate degree at the University of California, Los Angeles (UCLA). His graduate training included a specialized fellowship in public health where his research focused on environmental health and health-care delivery and management.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• What are the basic functions of the liver?
• What are common liver blood tests?
• What are the aminotransferases?
• Normally, where are the aminotransferases?
• What are normal levels of AST and ALT?
• What do elevated liver tests (AST and ALT) mean?
• Does AST and ALT measurements indicate liver function?
• Which blood tests are done to detect liver function?
• What are some common reasons for abnormal liver tests?
• What medications can cause abnormal aminotransferase levels?
• What conditions can cause very high aminotransferase levels?
• What are some of the less common causes of elevated liver blood tests?
• How are healthy people evaluated for mild to moderate rises in aminotransferase levels?
• How about monitoring liver blood tests?
• What about the other liver enzymes?
• Hepatitis Slideshow Pictures
• Take the Alcohol Quiz
• Alcohol Abuse Slideshow Pictures
• Patient Comments: Liver Blood Tests - Why Were You Tested?
• Patient Comments: Liver Blood Tests - Test
• Patient Comments: Liver Blood Tests - Diagnosis
• Liver Blood Tests Index

What conditions can cause very high aminotransferase levels?

AST and ALT serum levels in some situations can range anywhere from ten times the upper limits of normal to thousands of units/liter The highest levels of AST and ALT are found with disorders that cause rapid death of numerous liver cells (extensive hepatic necrosis). Although this degree of liver enzymes elevation is not common, it can occur in such conditions as:

• Acute viral hepatitis A or B
  
  
• Profound liver damage inflicted by toxins as from an overdose of acetaminophen (brand-name Tylenol) or mushroom poisoning
  
  
• Prolonged collapse of the circulatory system (shock) when the liver is deprived of fresh blood providing oxygen and nutrients

Also, very high AST and ALT levels can be a result of severe muscle diseases.

What are some of the less common causes of elevated liver blood tests?

Less common causes of abnormal liver enzymes in the United States include hemachromatosis (iron overload), Wilson's disease, alpha-1-antitrypsin deficiency, celiac disease, Crohn's disease, ulcerative colitis, and autoimmune hepatitis. Though not as common as hepatitis C, hepatitis B can cause chronic liver disease with persistently abnormal liver enzymes.

• Hemachromatosis is a genetic (inherited) disorder in which there is excessive absorption of dietary iron leading to accumulation of iron in the liver with resultant inflammation and scarring of the liver.
  
  
• Wilson's disease is an inherited disorder with excessive accumulation of copper in diverse tissues including the liver and the brain. Copper in liver can lead to chronic liver inflammation, while copper in brain can cause psychiatric and motor disturbances.
  
  
• Alpha-1-antitrypsin deficiency is an inherited disorder in which the lack of a glycoprotein (carbohydrate-protein complex) called alpha-1-antitrypsin lead to chronic lung disease (emphysema) and liver disease.
  
  
• Autoimmune hepatitis results from liver injury brought about by the body's own antibodies and defense systems attacking the liver.
  
  
• Celiac disease is a disease of the small intestine where a person has an allergy to gluten and develops gas, bloating, diarrhea, and in advanced cases malnutrition. Patients' with celiac sprue can also develop mildly abnormal ALT and AST levels.
  
  
• Crohn's disease and ulcerative colitis are diseases with chronic inflammation of the intestines (also referred to as inflammatory bowel diseases). In these individuals inflammation of the liver (hepatitis) or bile ducts (primary sclerosing cholangitis) also can occur, causing abnormal liver tests.
  
  
• Viral infections other than common hepatitis viruses (A, B, C) can sometimes cause elevation of liver enzymes as they can result in generalized body infection and liver inflammation.

Rarely, abnormal liver enzymes can be a sign of cancer in the liver. Cancer arising from liver cells is called hepatocellular carcinoma or hepatoma. Cancers spreading to the liver from other organs (such as colon, pancreas, stomach, etc) are called metastatic malignancies (to the liver).