Everyone Should Know Their Blood Type: 3 Ways to Find Yours

Two years ago, I was filling out a volunteer application at a children’s hospital and on the form, I was asked to give my blood type. Fortunately, I knew for sure that I was writing O-positive, but I was looking for documents to confirm this information. I called my mom to see if the blood type was listed on my birth certificate — no luck. I checked my doctor’s health site — and no luck.

This made me wonder: How does one find out their blood type if they don’t know it?

Your ignorance blood type it can be a problem when it comes to your whole life. Regardless of your age or health, it is important to know whether you are typing A, B or O. Having this information can be very important in a medical emergency, and it makes donating blood or filling out certain forms much easier.

If you don’t know what type you are, you’re not alone. According to a 2019 CBS News poll, only 66% of Americans reported knowing their blood type. Considering your blood type can be important in understanding your health, including your own heart health — and to save your life in an emergency — it’s important to know what type of blood vessels are in your veins. The good news is finding out your blood type is easy and you have options. Below are three simple ways to find out your blood type.

Basics of blood type

Blood type is divided into eight groups: A-positive, A-negative, B-positive, B-negative, O-positive, O-negative, AB-positive and AB-negative. But what determines blood type and what does that blood type mean?

Blood types are determined by antigens — the substance that triggers the body’s immune response — on the surface of red blood cells. There are ABO antigens, which indicate ABO blood types. This is determined by the ABO gene. For example:

• Type A blood type has A antigen
• Type B blood type has B antigen
• Type AB blood type has both A and B antigens
• Type O does not produce A or B antigen

There are also Rhesus (Rh) antigens, which determine whether the blood is “good” or “bad.” If you have Rh proteins on the surface of your red blood cells, you are Rh positive. If you don’t have the Rh protein on your red blood cells, you have bad blood.

How can you find out your blood type?

Here are three main ways to type your blood:

• Ask your doctor for a blood test
• Donate blood
• Use a blood test at home

1. Clinical examination

One of the easiest and most effective ways to determine your blood type is to have your doctor test you. The technician will draw blood and perform two tests on the blood sample: forward typing and reverse typing.

During forward typing, the blood sample is mixed with antibodies against type A and B blood. Based on whether the blood cells stick together when they are mixed with the immune system, your blood type can be determined from there. If your blood cells stick together when combined with antibodies against type B blood, you have type B blood. If your blood cells stick together when combined with antibodies against type A blood, you have type A blood.

To confirm the result, the next step is reverse typing, which means that a blood sample without red blood cells — called serum — is mixed with type A and type B blood cells. Type A blood will have antibodies against Type B blood in the sample and Type B blood will have antibodies against Type A blood. Type O blood will contain antibodies against Type A and Type B. So, if adhesion occurs when the serum is mixed with Type B blood cells, you have type A blood, and if adhesion occurs when the serum is mixed with type A blood cells, you have type B blood.

I recommend that you call your doctor’s office to see how much the blood type test costs out of pocket and if it is covered by insurance.

2. Donate blood

This is a simple — and free — way to determine blood type, but the results are not fast.

If you donate to a blood drive, you can simply ask the staff about your blood type. Blood is usually not tested immediately, so it may take several weeks to get results.

3. Blood test at home

Home testing is relatively straightforward. You will usually start by wiping your finger with alcohol and then need to prick your finger with a disposable lancet to draw blood. After that, you will wipe the blood from the given card. Depending on how the blood dries, clots or spreads, you will be able to compare the color of your blood to the score card. In a few minutes, you will be able to determine your blood type.

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