Blood Testing

Blood testing is usually done as part of a routine checkup, says the National Institutes of Health (NIH). Anyone who gets an annual checkup or physical exam from their healthcare provider may undergo blood testing during their appointment, adds the NLM. However, some people may require more frequent blood testing based on their health status or if they have certain conditions that require close monitoring. Additionally, blood tests can be used to help diagnose certain medical conditions.

According to the BLM, blood testing may be used to:

• Diagnose or rule out diseases and conditions, including blood clot disorders
• Monitor a chronic condition such as diabetes or high cholesterol
• Find out whether a treatment is working
• Check how well certain organs are working, such as the heart and liver
• Find out whether the immune system is effectively fighting infections

Your general physician may suggest getting a blood test if you meet risk factors for certain conditions or if further testing is needed to diagnose a suspected health condition. If you have a chronic condition like diabetes, you may need routine blood testing to stay healthy and reduce your risk for complications.

The NLM says that in some instances, blood testing may not provide your doctor with enough information about your condition. It adds that you may need other diagnostic tests in addition to blood work to gain a proper diagnosis. Your doctor can talk to you in greater detail about how often you need blood testing.

Blood tests are usually ordered by your doctor, who will give you a referral to a hospital or lab that can perform the test and evaluate your blood sample. Some lab service providers may do blood testing without a doctor’s referral, though the cost of the test may not be covered by health insurance if it is not ordered by your doctor.

Consult with your doctor beforehand if you think you may need a blood test. Your doctor can confirm whether blood testing is necessary and refer you to a lab that can do your blood work. You can also use Solv to browse the highest-rated blood testing providers near you.

Some blood tests can also be performed using at-home test kits purchased from a local pharmacy or online retailer. Ask your doctor for guidance if you’re not sure how to go about getting the type of blood test you need.

There are many types of blood tests, though complete blood count (CBC), basic metabolic panel, and blood enzyme tests are some of the most common blood tests, reports the NLM and NIH.

Complete Blood Count (CBC)

A CBC is usually performed during regular checkups and measures different parts of your blood, including red and white blood cells, platelets, and hemoglobin. It also measures hematocrit and mean corpuscular volume—which is a measure of the average size of your red blood cells, reports the NLM. CBCs may be used to diagnose or monitor sickle cell disease, anemia, and blood clotting disorders, says the NIH.

Basic Metabolic Panel (BMP)

A basic metabolic panel measures the amount of certain chemicals in your blood, such as electrolytes and glucose, says the NLM. Also known as a blood chemistry test, a basic metabolic panel may be performed to diagnose or monitor high blood pressure or heart failure. Sometimes, this blood test may require you to fast beforehand—just be sure to ask your doctor whether fasting is required.

Blood Enzyme Tests

Blood enzyme tests check for levels of certain enzymes in your blood and are usually performed to screen for heart attacks. The most common types of blood enzyme tests are troponin and creatine kinase tests, adds the NLM.

Lipoprotein panels, blood clotting tests, and bone marrow tests are other common blood tests, according to the NIH. A lipoprotein panel measures your cholesterol levels and triglyceride levels, and it may also be used to screen for atherosclerosis and coronary heart disease. Blood clotting tests may be used to monitor bleeding and platelet disorders. Your doctor can recommend the best type of blood test for you based on your health situation.

During blood testing, a lab professional will draw a small amount of blood from a vein in your arm. The provider will use a tiny needle to draw the sample, which is collected into a vial or test tube. You may feel a slight sting as the needle is inserted into your skin. In most instances, blood testing takes under five minutes, reports the NLM.

Blood testing may also be performed as a finger prick test, heel stick test, or arterial blood test, adds the NLM.

A finger prick test involves the use of a small device that simply pricks the fingertip to gather a small sample of blood. A heel stick test is usually only performed on newborns and involves poking the heel with a small needle to collect a blood sample. An arterial blood test is performed to measure your blood oxygen levels and may cause pain that is sharper than a traditional blood test, according to the NLM. This test is typically reserved for those that are very ill.

Most blood tests do not require any special preparation, reports the NLM. However, some types of blood tests may require you to fast for several hours beforehand.

Glucose tests and lipid tests are the most common types of blood tests that require you to fast, says the NLM. Fasting requires you to refrain from eating any foods or drinking any beverages other than water for between eight and 12 hours before your test.

Your doctor or lab testing provider will usually let you know if you are required to fast before your blood test.