Why do doctors order laboratory tests?
A doctor could have all sorts of reasons for ordering a lab test, from diagnosing a disease and planning your treatment to monitoring your health. Tests can be used to check for routine things such as cholesterol in the blood or protein levels in the urine to see if your results are in the normal range. If you're not feeling well and the cause is unclear, a lab test of blood or urine may help pinpoint the cause. And if you're already being treated for an illness, a lab test can help track the effectiveness of the treatment.
What do the results mean?
This is what you should talk over with your doctor. After your blood or urine sample has been analyzed, you'll eventually receive the results. Unless you really know your medicine, there's a good chance that the raw numbers won't mean that much to you. For this reason, the results will probably be labeled with descriptive words like high, normal, or low. Normal means that you have the numbers expected for a generally healthy person your age. High or low readings mean that something is out of line. High numbers aren't always bad; if you're talking about good cholesterol, for instance, the higher the better. For this reason, you'll have to talk to your doctor to know if your results are normal or whether there is any cause for concern.
How will my tests be used?
Laboratory tests are used to paint a full picture of your health. Your doctor will likely have to look at more than one or two test results to decide if you need treatment and, if so, which treatment would work best.
To help your doctor get the clearest picture possible, it's important to tell him or her about your medical history and your current health.
Questions to ask about lab tests
It's also very important that you ask questions of your own. The right questions might help you avoid unnecessary tests. By staying informed, you'll also get the most from the tests that you really do need.
Here are the key questions to ask your doctor:
- What tests are you ordering?
- How much will the test cost? Are they covered by my health insurance?
- Is there a less-expensive alternative?
- What do you expect to find out from these tests?
- How long will it take for results to come in? When will you contact me about them?
- When should I call if I don't hear from you?
- Do I have to do anything special to prepare for any of the tests?
- Do these tests have any side effects or risks?
- Will I need more tests later on?
Agency for Healthcare Research and Quality. Asking questions about medical tests. http://www.ahrq.gov/consumer/cc/cc020508.htm
American Association for Clinical Chemistry. http://www.labtestsonline.org/understanding/
U.S. Food and Drug Administration. Laboratory tests. https://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/InVitroDiagnostics/LabTest/default.htm
FDA-Approved Home and Lab Tests, 2017. https://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/InVitroDiagnostics/LabTest/ucm126079.htm