What kinds of blood tests are there, and how long does it take to get my results?
Once you leave the lab, how long will it take to get results of your bloodwork? It depends on several factors.
Doctors use the results of your blood tests to get a better picture of your overall health and understand more about what’s going on inside. There are many things a blood test can show you — such as cholesterol or blood sugar levels. Reading results and communicating them to you can take a matter of hours, days or weeks.
Tests and when to expect results
- Complete blood count (CBC)— This test measures components of the blood: white blood cells, red blood cells and platelets. It also checks the hemoglobin in the red blood cells and measures the hematocrit, or the proportion of red cells in the blood. CBC results are usually available to your doctor within 24 hours.
- Basic metabolic panel— This measures common electrolytes and other compounds in the blood, including calcium, glucose, sodium, potassium, carbon dioxide and creatinine. These results are typically sent to your doctor within 24 hours.
- Complete metabolic panel— This blood test measures all the factors mentioned in the basic metabolic panel as well as two protein tests, albumin and total protein, and four tests of liver function (ALP, ALT, AST, and bilirubin). A provider may order this more comprehensive testing to understand more about your liver or kidney function. They’ll usually receive your results within one to three days.
- Lipid panel— Lipid panels measure the amount of cholesterol in the body. This includes high-density lipoprotein (HDL) and low-density lipoprotein (LDL). Your provider should receive results from the lab within 24 hours.
- Thyroid panel — These tests look for the presence of thyroid hormone, such as thyroid-stimulating hormone (TSH), in the blood. Your provider may wish to have a thyroid panel done to see if you have a medical condition affecting your thyroid, such as hyperthyroidism or hypothyroidism. These results should be sent to your provider within one to two days, so you can usually expect to learn your levels within a week.
- Cancer — There are several different blood test types to detect for the possible presence of cancer. The blood tests recommended depend on the type of cancer. Some of these tests can be rarer, as for certain types of immunoglobulins and tumor markers. Results of these tests can take days to a week or more before results are available.
- Sexually transmitted infection (STI) tests — Rapid testing is available for HIV tests, usually at community health centers and clinics. Doctors also use blood tests to test for the presence of conditions such as herpes, hepatitis and syphilis. These results may take up to one to two weeks. If swabs or urine testing are preferred for the type of STI you may have, results will take longer because swabs are used to grow cultures. Some STIs don’t show up immediately after they’re transmitted, so your provider may order a follow-up test a certain period of time after a negative result.
How will I learn about my test results?
Lab personnel will usually call or send results directly to a provider’s office for review. If the provider has a lab on-site, some tests may be run there. Some labs will release your results to an online portal without a doctor’s review.
Results may be delayed if the sample is inadequate (not enough blood) or is contaminated, or if the blood cells were destroyed for some reason before reaching the lab.
Some tests require you to fast (stop eating) for a certain period of time, usually eight hours. If you are not fasting, the test may not be performed since eating affects the outcome of the test. You may need to come back for a blood draw, which will further delay results of some tests.
Many of these tests are performed during an annual physical.