Normal ALT levels are between 7 and 55 units per liter, and normal AST levels are between 8 and 48 units per liter, according to Mayo Clinic. ALP levels should be between 45 and 115 units per liter, and albumin should be between 3.5 and 5.0 grams per deciliter.
Bilirubin levels should be between 0.1 and 1.0 milligrams per deciliter in a normal individual, according to Mayo Clinic. GGT levels should be between 9 and 49 units per liter, LD between 122 and 222 units per liter, and PR between 9.5 and 13.8 seconds. Normal results may vary slightly between laboratories and women and children may have normal levels slightly outside of these ranges. The further a patient's test results are from the normal ranges, the greater the risk of liver disease.
To administer a blood test for liver function, a healthcare provider draws blood from a vein in the arm, explains Mayo Clinic. This blood is sent to a laboratory for analysis, and the results are given to the patients within several hours to several days. Patients may be asked to avoid food and certain medications prior to a liver function test and should obey doctors' orders in this regard, since certain medications and foods can affect the results. There are few risks associated with a liver function test, although some patients experience minor soreness at the needle site.