Lab Values Pro: Lab Reference Login

Listing Results Lab Values Pro: Lab Reference Login

Frequently Asked Questions

• Why are there no reference values for lab tests?

  While accuracy of laboratory testing has significantly evolved over the past few decades, some lab-to-lab variability can occur due to differences in testing equipment, chemical reagents used, and analysis techniques. Consequently, for most lab tests, there is no universally applicable reference value.

• Where can I find the reference range for my test results?

  To evaluate whether your numbers are within normal limits, it is best to refer to the reference range printed on the report you receive from the laboratory that performed your tests. A report will typically display your results followed by that lab’s reference intervals for each test performed.

• What do the reference ranges on a lab report mean?

  The specific reference ranges that appear on your laboratory report are determined and provided by the laboratory that performed your test. Reference ranges help describe what is typical for a particular group of people based on age, sex, and other characteristics.

• Do you have to use a normal range for a lab test?

  A normal result in one lab may be abnormal in another: You must use the range supplied by the laboratory that performed your test to evaluate whether your results are “within normal limits.”

• Why do reference values vary in a laboratory?

  (N ote: The reference values provided in these tables should be used as guidelines only.) Reference values vary based on several factors, including the demographics of the healthy population from which specimens were obtained and the specific methods and/or instruments used to assay these specimens.

• When was the Merck Manual first published in the US?

  The Merck Manual was first published in 1899 as a service to the community. The legacy of this great resource continues as the Merck Manual in the US and Canada and the MSD Manual in the remainder of the world.

• How are the values of blood tests determined?

  Reference values vary based on several factors, including the specific laboratory that supplies them. A patient's blood test values should be interpreted based on the reference value of the laboratory in which the test was done; the laboratory typically provides these values with the test result.

• How are the results of a laboratory test interpreted?

  A patient's laboratory test values should be interpreted based on the reference value of the laboratory in which the test was done; the laboratory typically provides these values with the test result. Some of these values are listed in alphabetical order in the following table. mckat = microkatal. NOTE: This is the Professional Version.