To find out your blood group, a sample of your blood has to be taken and tested. However, GPs do not routinely check people's blood groups.
You can also find out your blood group by giving blood.
When is someone's blood group checked?
Healthcare professionals sometimes need to know a person's blood group for medical reasons.
If you need a blood transfusion, the blood group you receive must be compatible with your own blood group.
Your blood will therefore be tested before you receive a blood transfusion to make sure you are given a matching blood group.
Giving someone blood from the wrong group can potentially be life threatening.
If you're pregnant it's also important to know if you are rhesus negative or positive. Find out more about rhesus disease.
Healthcare professionals will also check a person's blood group before they:
- give blood
- have an operation (surgery)
- donate an organ for transplant
Give blood and find out your blood group
Your blood group will be checked if you give blood through NHS Blood and Transplant, and it will be recorded on your official donor card.
This is so your blood can be matched to someone with the same blood group or a group that is compatible.
Blood type is categorized into one of these 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 -- a substance that triggers an immune response -- on the surface of red blood cells. There are ABO antigens, which designate ABO blood types. This is determined by the ABO gene. For example:
- Type A blood type has the A antigen
- Type B blood type has the B antigen
- Type AB blood type has both the A and B antigen
- Type O doesn't produce any A or B antigen
There are also Rhesus (Rh) antigens, which determine if blood is "positive" or "negative." If you have Rh proteins on the surface of your red blood cells, you are Rh positive. If you don't have Rh proteins on the surface of your red blood cells, you have negative blood.
Read also: 5 Unexpected Reasons You Get So Many Mosquito Bites: Blood Type, Clothing and More
Blood type is categorized into one of these eight groups: A-positive, A-negative, B-positive, B-negative, O-positive, O-negative, AB-positive and AB-negative.
Ekachai Lohacamonchai/EyeEm/Getty ImagesHow can you type your blood?
Here's three main ways to type your blood:
- Have your doctor do a blood test
- Donate blood
- Use an at-home blood test
Read also: Should You Eat Based On Your Blood Type? What Experts Say
1. Clinical test
One of the easiest and most effective ways to determine blood type is to have your doctor perform a test. A professional will draw blood and then 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 mixed with the antibodies, your blood type can be determined from there. If your blood cells stick together when mixed with antibodies against type B blood, you have type B blood. If your blood cells stick together when mixed with antibodies against type A blood, you have type A blood.
To confirm the result, the next step is reverse typing, meaning the blood sample without red blood cells -- called a 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 sticking occurs when the serum is mixed with type B blood cells, you have type A blood, and if sticking occurs when the serum is mixed with type A blood cells, you have type B blood.
I recommend calling your doctor's office to see what a blood type test costs out-of-pocket and if it's covered by insurance.
2. Donate blood
This is an easy -- and free -- way to determine blood type, but results are not immediate.
If you donate to a blood drive, you can simply ask the staff about your blood type. Blood usually is not tested right away, so it may take up to a few weeks to get results.
With at-home kits, you can determine blood type in the comfort of your own home in just a few minutes.
3. At-home blood test
At-home tests are relatively straightforward. You will usually start by wiping your finger with an alcohol wipe and then be required to prick your finger with a disposable lancet to draw blood. Then, you will wipe blood on the provided card. Depending on how the blood dries, clumps or spreads, you will be able to compare your blood stain to a results card. Within minutes, you'll be able to determine which blood type you are.
At-Home Blood Type Kits
$17 at Walmart
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The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.