Liver enzymes are special chemicals used in the liver to perform essential functions. These enzymes, which include ALT and AST, are usually contained within the liver cells, and can only be seen in the blood when those cells have become damaged or inflamed. Liver function tests are blood tests that measure liver enzymes within the blood. Usually elevated liver enzymes indicate a transient liver inflammation, but can also point to a more chronic liver disease.
Jaundice
Jaundice is a yellowing of the skin and sclera, which is the white part of the eye. This is a common symptom associated with liver disease, reports the University of Maryland Medical Center. Jaundice is caused by an increase in the yellow pigment called bilirubin within the blood. Bilirubin is a pigment that is often contained within the liver that is released in the bile salts. When the liver becomes damaged, bilirubin along with the ALT and AST leaks into the blood. The bilirubin can enter the cells of the skin and sclera and cause jaundice.
Abdominal Pain
Elevated liver enzymes can be diagnostic for viral hepatitis, according to LiverDisease.com. Viral hepatitis, like hepatitis A or B, is a disease that causes inflammation and damage to the liver cells. The virus can cause the cells to die. Often this results in a release of liver enzymes associated with abdominal pain, reports the National Digestive Diseases Information Clearinghouse. The abdominal pain is often located in the upper right quadrant of the abdomen. The abdominal pain is caused by inflammation of the liver. The pain can range from mild to severe. Abdominal pain associated with elevated liver enzymes indicates a high probability of liver disease.
Weight Loss
An elevation of liver enzymes can indicate non-alcoholic fatty liver disease, states MayoClinic.com. A chief symptom of this disease is weight loss and it can be diagnosed by testing for increased liver enzymes. The weight loss is seen even in patients who are attempting to gain weight. Nonalcoholic fatty liver disease can lead to liver failure. Therefore, patients with weight loss associated with elevated liver enzymes should immediately consult their physician.
Cholestasis
Cholestasis is the obstruction or blockage of bile flow inside or outside of the liver, according to the University of Maryland Medical Center. Often this is caused by inflammation of the liver cells. The enlargement of the liver cells causes the bile ducts within the liver to close and therefore, the bile continues to build up within the liver.
References
- University of Maryland Medical Center: Liver Disease
- MayoClinic: Nonalcoholic Fatty Liver Disease -- Definition
- MayoClinic: Nonalcoholic Fatty Liver Disease -- Tests and Diagnosis
- National Digestive Diseases Information Clearinghouse: Viral Hepatitis: A through E and Beyond
- LiverDisease.com: Liver Enzymes
