Lab tests are used in many different ways. Your health care provider may order one or more lab tests to:
Diagnose or rule out a specific disease or condition
Screen - A screening test can show if you are at a higher risk for getting a specific disease. It can also find out if you have a disease, even if you have no symptoms.
Monitor a disease and/or treatment - If you've already been diagnosed with a disease, lab tests can show if your condition is getting better or worse. It can also show if your treatment is working.
Check your overall health - Lab tests are often included in a routine checkup.
Lab results are often shown as a set of numbers known as a reference range. A reference range may also be called "normal values." You may see something like this on your results: "normal: 77-99mg/dL". Reference ranges are based on the normal test results of a large group of healthy people. The range helps show what a typical normal result looks like. But not everyone is typical. Sometimes, healthy people get results outside the reference range, while people with health problems can have results in the normal range. If your results fall outside the reference range, or if you have symptoms despite a normal result, you will likely need more testing. Your lab results may also include one of these terms:
- Negative or normal, which means the disease or substance being tested was not found
- Positive or abnormal, which means the disease or substance was found
- Inconclusive or uncertain, which means there wasn't enough information in the results to diagnose or rule out a disease. If you get an inconclusive result, you will probably get more tests. Tests that measure various organs and systems often give results as reference ranges, while tests that diagnose or rule out diseases often use the terms listed above.
If you have any questions about your lab tests or what your results mean, talk to your health care provider.
There are two ranges that I use in my practice – the reference range noted above and the optimal range, which is generally much tighter. The optimal range helps predict disease earlier and is needed as the “large group of healthy people” used for reference is less and less healthy. Additionally, some reference ranges are skewed. For example the reference range for total cholesterol is too strict, while the range for TSH (thyroid stimulating hormone) is too broad.
Blood chemistry testing is the best screening tool for any new patient. It is the best way to determine several nutritional deficiencies and health issues. It also serves as an objective tool to determine success or failure with nutritional protocols.
I am an advocate of yearly blood chemistry testing for all the reasons noted above. As a minimum, I recommend a CBC, comprehensive metabolic profile, lipid panel, magnesium, T3, T4, TSH and urine analysis. However, I typically add a hemoglobin A1c, homocysteine, hs-CRP, insulin, and vitamin D to throw a broader net for aspects of metabolic syndrome.
Source: April 15, 2019 NIH