Your liver is the largest internal organ in your body. It performs many essential functions, including storage of digested nutrients; production of important blood proteins such as albumin and clotting factors; removal of toxic compounds, drugs and hormones from your blood; and production of bile to help digest fatty foods. A blood test that measures the levels of liver enzymes may detect several liver disorders with few early symptoms. These disorders include hepatitis, cirrhosis and liver cancer.
Liver Enzymes
A routine blood test can measure the levels of alanine transaminase, or ALT, and aspartate transaminase, or AST, enzymes contained inside normal, healthy liver cells. Since liver cells occasionally die in a healthy liver, a low blood level of these enzymes is normal. However, abnormally high levels of liver enzymes in a blood test may indicate any one of several liver disorders. According to MayoClinic.com, ALT and AST are considered elevated if blood levels exceed 55 units and 48 units per liter, respectively.
Cirrhosis
Cirrhosis is a disorder in which a portion of your liver is damaged and replaced by scar tissue. It can result from heavy alcohol use, taking certain drugs or having a liver infection. Cirrhosis in its early stages often has few symptoms, but elevated liver enzymes in your blood may suggest that liver cells are dying as scar tissue is building. Eventually, cirrhosis causes fatigue, loss of appetite, weight loss or frequent bruising of your skin without an injury. If cirrhosis is mild and discovered early, the liver is able to repair itself and stop more damage from occurring.
Hepatitis
Hepatitis is an inflammation of the liver that may interfere with liver function. Hepatitis is usually caused by a virus, the most common being hepatitis A, B or C. Symptoms may include jaundice, fatigue, abdominal pain, anorexia, nausea, vomiting and low grade fever. It may take years for symptoms of hepatitis infection to appear. Elevated liver enzymes in a blood test may suggest hepatitis is present, even in the early stages. If so, a liver biopsy may be carried out to confirm the diagnosis.
Liver Cancer
Liver cancer originates in the liver rather than beginning elsewhere and eventually spreading to the liver. As the cancer grows and destroys normal liver cells, levels of liver enzymes in the blood usually rise. There are several forms of liver cancer, depending of the type of cell involved and the location of the malignant mass. Sometimes, liver cancer is without definite symptoms, and a blood test with high liver enzymes is the first sign of a problem. Doctors may do imaging studies and a biopsy to confirm the disorder.
References
- MayoClinic.com: Elevated Liver Enzymes
- MayoClinic.com: Liver Problems
- National Digestive Diseases Information Clearinghouse: Viral Hepatitis: A Through E and Beyond
- National Diabetes Information Clearinghouse: What I Need to Know About Cirrhosis
- ElevatedLiverEnzymes.net: Elevated Liver Enzymes
- American Liver Foundation: Liver Cancer
