Information on blood test results are available in the What Do Blood Tests Show section of the website of the National Heart, Lung and Blood Institute. Other options include MerckManuals.com and the patient's lab report, which typically shows a range of normal results, notes the American Association for Clinical Chemistry.
To determine whether a blood test result is within the normal range, compare the results to the ranges provided on the report by the laboratory that performed the test, advises American Association for Clinical Chemistry. Laboratories base these ranges on the test results of 95 percent of healthy individuals within a particular group, and they often vary based on differences in gender, age and race. For example, the normal hematocrit range is 36 to 44 percent for females and 41 to 50 percent for males, notes the National Heart Lung and Blood Institute.