How to Figure Out Your Blood Type

Ask a person of a certain age what their blood type is, and chance are they’ll know it offhand. From military dog tags to Cold War-era tattoos on children, the idea was that knowing your blood type could save your life in an emergency situation where you might need blood immediately. But what used to be a crucial piece of personal information that people could rattle off alongside their date of birth, home address and Social Security number, is no longer something everyone knows or remembers.

Blood type has been in the news again recently thanks to COVID-19. Initially, some thought there might be a connection between blood type and the severity of COVID symptoms, but a new study from Harvard University found that this is not the case. Even so, given all the other potential complications with the diagnosis, it’s a good idea to know your blood type. So, do you have one of the eight most common blood types (A+, A-, B+, B-, O+, O-, AB+, AB-), or one that’s rare? Here’s how to figure it out.

How to find your blood type

For some background on what blood types are, why they matter, and the characteristics of each type, the Red Cross has a very helpful section of their website that breaks everything down. For now, here are a few ways to learn your blood type.

Donate blood

If you’re in a position where you can donate blood, doing so is a great way to find out your blood type because you get the information you need and help others at the same time. Once you’ve donated, they’ll give you a blood donor card which will give you access to your blood type via their website. It usually takes a few days after you’ve donated for your blood type to show up, but it’s free.

Ask your doctor

Your general practitioner may have your blood type on file from previous lab work. You can always call their office to see if they can tell you what it is. Not every medical facility will have this information, but it’s worth a shot.

Get bloodwork done

If you’ve been meaning to get bloodwork done anyway, you can request that they also let you know what your blood type is while they’re doing the rest of the testing.

Take an at-home blood type test

There are a range of at-home tests that determine your blood type. You can ask about these at your local pharmacy or order them online for around $30 per test.

Skip the saliva test

Technically, there are saliva tests available if you’re someone who would rather skip any sort of needle or skin prick. According to a 2016 study published in the Journal of Clinical & Diagnostic Research, around 80% of people have the same antigens in their saliva as they have in their blood. But for something like blood type, being correct 80% of the time isn’t ideal. Given that this isn’t the most accurate way, you’re probably better off skipping this one.