Bilirubin

• Bilirubin is the normal byproduct when the liver breaks down worn-out red blood cells. Total bilirubin testing measures the amount in the blood stream. According to the Centers for Disease Control and Prevention, normal bilirubin is between .20 and 1.50 milligrams per deciliter. Direct bilirubin measures the amount manufactured by the liver and should range from .00 to .03 mg/dl.
  
  

Liver proteins

• Blood tests can measure a wide range of liver functions. The results help doctors diagnose disease.
  
  Total protein, also called serum total protein, measures proteins in the bloodstream. Levels are considered normal from 6.5 to 8.2 grams per deciliter.
  
  Albumin is a protein manufactured by the liver that helps contain blood within the circulatory system. Low albumin levels, which indicate liver damage, can allow fluid to leak into surround tissue. This causes swelling in the ankles and feet of patients with liver disease. Look for normal ranges of 3.9 grams/ deciliter to 5.0 grams/deciliter, according to the CDC.
  
  Globulins are disease-fighting proteins manufactured by the liver that also move fat and certain nutrients in the bloodstream. Normal levels are from 2.2 to 4.2 g/dl.
  
  Prothrombin, also called Factor II by hematologists, is a protein manufactured by the liver that causes blood clot. The test for this protein is measured in time--how long it takes the blood sample to clot---instead of units per deciliter. Normal clotting time is between 10 and 15 seconds.
  
  Albumin/globulin ratio measures the two proteins in relation to one another. According to the CDC, a healthy range is 0.8 to 2.0.
  
  

Liver enzymes

• ALT, also called alanine aminotransferase, helps the liver use amino acids to build protein. Look for normal levels between 5 and 60 international units per liter.
  
  AST, also called aspartate aminotransferase, is another substance used to create protein from amino acids. The normal range is 5 IU/L to 43 IU/L.
  
  

Cholestatic liver enzymes

• Hemaglobin
  
  ALP, also called alkaline phosphatase, is found in other organs such as the kidneys, and it is also found in bones. Levels are considered normal when they range from 30 IU/L to 115 IU/L.
  
  GGT, gamma-glutamyl transpeptidase, is manufactured in the liver. Normal range is from 5 IU/L to 80 IU/L.
  
  

Considerations

• The normal values listed in this fact sheet are for healthy adults. Discuss the results of your test with your doctor, who can best advise you on what they mean and how to change factors that might have made your results unusual.
  
  

Warning

• Blood smples
  
  Do not rely on the Internet for medical advice. Always seek your doctor's advice on how to treat illness.