From cholesterol levels to blood counts, there are many blood tests available. Sometimes, results are available within minutes of performing the test. In other instances, it can take days or weeks to obtain blood test results.
How soon you can learn your levels really depends on the test itself and a number of other factors.
A blood draw is also known as a venipuncture. The procedure involves taking blood from a vein. Medical personnel known as phlebotomists most commonly perform blood draws. To take your blood, they’ll:
- Wash their hands with soap and water or hand sanitizer and apply gloves.
- Place a tourniquet (usually a stretchy, rubber band) around a location, usually on your arm.
- Identify a vein and clean the area off with an alcohol wipe.
- Insert a small, hollow needle into the vein. You should see blood coming through the needle and into a collection tube or syringe.
- Remove the tourniquet and hold gentle pressure on the venipuncture site. Sometimes, they’ll place a bandage over the site.
The blood draw process can be very quick if you have veins that are easily visualized and accessed. The process usually takes 5 to 10 minutes.
However, sometimes it may take more time to identify a vein. Factors such as dehydration, the experience of the phlebotomist, and the size of your veins can impact how quickly a blood draw can be done.
Some of the more common blood tests a doctor may order include:
- Complete blood count (CBC). This test measures the presence of 10 cell types in the white blood cells, red blood cells, and platelets. Examples of these results include hematocrit, hemoglobin, red blood cell count, and white blood cell count. CBC results are usually available to your doctor within 24 hours.
- Basic metabolic panel. This test measures common electrolytes in the blood as well as other compounds. Examples include calcium, glucose, sodium, potassium, carbon dioxide, chloride, blood urea nitrogen, and creatinine. You may be asked to fast for a certain period of time before having your blood drawn. These results are also typically sent to your doctor within 24 hours.
- Complete metabolic panel. This blood test measures all the factors mentioned in the test above as well as two protein tests, albumin and total protein, as well as four tests of liver function. These include ALP, ALT, AST, and bilirubin. A doctor may order this more comprehensive testing if they wish 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 doctor should receive results from the lab within 24 hours.
Often a laboratory’s personnel will call or transmit results directly to a doctor’s office for their review. Depending on your doctor’s schedule, you may learn your results via a phone call or online portal shortly after the doctor’s office receives them. However, you should be prepared to allow more time.
Some labs will release results directly to you via a secure online portal without your doctor’s review. In this case, the lab can tell you when to expect results.
Your results may be delayed if the sample is inadequate (not enough blood), contaminated, or if the blood cells were destroyed for some reason before reaching the lab.
Pregnancy blood test
Pregnancy blood tests are typically quantitative or qualitative. A qualitative blood test delivers a “yes” or “no” result to a pregnancy. A quantitiative blood test can answer how much human chorionic gonadotropin (hCG) is present in the body. This hormone is produced during pregnancy.
The time it takes for these tests to result can vary. If a doctor has an in-house laboratory, you may receive your result in a few hours. If not, it could take two to three days. Both tests take longer than a pregnancy urine test. That test typically gives results in minutes, but is less precise.
Other measurements include T3 uptake, thyroxine (T4), and free-T4 index, also known as T7. A doctor would order this test to determine if a person has a medical condition affecting their thyroid, such as hyperthyroidism or hypothyroidism.
These results should be sent to your doctor within one to two days, so you can usually expect to learn your levels within a week.
Doctors may use several different blood test types to detect for the possible presence of cancers. The blood tests recommended depend on the type of cancer your doctor is looking for. Some of these tests can be rarer, as is the case for certain types of immunoglobulins and tumor markers.
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, often at community health centers and clinics. According to Columbia University, these tests most commonly provide results in 10 to 20 minutes. 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.
Be aware that swabs (of either the genital area or inside the mouth) and urine tests may be the preferred method for some STI testing. Results can also take longer if cultures need to be grown.
Some STIs don’t show up immediately after they’re transmitted, so your doctor may order a follow-up test a certain period of time after a negative result.
A doctor could order a CBC to test for anemia or order fewer tests by requesting a hemoglobin and hematocrit (H and H) test. Rapid testing for these results is available, with levels sometimes reported in 10 minutes or less. However, other laboratory tests may take hours to result.
Location can play a factor into how fast you’ll get your results back. For example, going to a place where there’s an on-site laboratory (such as a hospital) may get you results more quickly than if your blood has to be sent to another laboratory. Specialty tests for rare conditions often need to be sent to specific laboratories.
According to Regional Medical Laboratory, most in-hospital results can be obtained within three to six hours after taking the blood. Sometimes blood drawn at other, non-hospital facilities can take several days to get results.
If you’re hoping to receive blood test results as quickly as possible, some tips to do this can include:
- Ask to have blood drawn at a location where there’s an on-site laboratory.
- Ask if there are “quick test” options for a particular test, such as an H and H for anemia.
- Ask if the results can be sent to you via a web portal.
- Ask if you can wait at the medical facility until results are available.
Sometimes, how quickly the blood tests take depends on how common the blood test is. Blood tests performed more often, such as a CBC or metabolic panel, are usually available more quickly than tests for rare conditions. Fewer laboratories may have the testing available for these conditions, which could slow results.
With innovations in quick testing, many more laboratory tests are available sooner than ever before. However, it’s often important that your doctor do a careful review before passing along the results. Asking a doctor or laboratory technicians about how long average tests will take can help you to establish a realistic time frame for getting results.
The AACC provides comprehensive information on blood tests in their guide.