# How do I find out my blood type? **URL:** \ **Category:** Factual Questions\ **Created:** [February 20, 2009, 7:28am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692 "2009-02-20T07:28:31Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![curlcoat](https://avatars.discourse-cdn.com/v4/letter/c/ea5d25/32.png) [@curlcoat](https://boards.straightdope.com/u/curlcoat)\ **Post date:** [February 20, 2009, 7:28am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/1 "2009-02-20T07:28:31Z")
I’d like to find out if I’m a candidate to donate a kidney to a friend and apparently the first step is to find out my blood type. I can’t do it thru being a blood donor because I am told I would have to give a “full bag” and since I clot like crazy, not likely to happen. I’d go to a regular lab, except I can’t get them to tell me how much it would cost! Any other ideas? ---
**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\ **Post date:** [February 20, 2009, 7:41am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/2 "2009-02-20T07:41:46Z")
Join the military and then read your ID card. ---
**Author:** ![Oakminster](https://avatars.discourse-cdn.com/v4/letter/o/77aa72/32.png) [@Oakminster](https://boards.straightdope.com/u/Oakminster)\ **Post date:** [February 20, 2009, 7:46am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/3 "2009-02-20T07:46:02Z")
It’s probably listed in your medical records if you have any. Might be listed on your birth certificate…or your mother may know, if she’s available. I remember doing a blood typing excercise in high school biology years ago…maybe there are kits available online? Yup…found via google, so buyer beware, but: [http://www.healthhometest.com/index.php](http://www.healthhometest.com/index.php) ---
**Author:** ![CairoCarol](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cairocarol/32/3825_2.png) [@CairoCarol](https://boards.straightdope.com/u/CairoCarol)\ **Post date:** [February 20, 2009, 7:49am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/4 "2009-02-20T07:49:12Z")
If you don’t mind me riding on the coattails of this thread, can I ask knowledgeable Dopers if it possible to know your blood type if you know that of both parents? My husband and I are both A+. Does this mean our son must be too, or are there other possibilities? ---
**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\ **Post date:** [February 20, 2009, 7:52am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/5 "2009-02-20T07:52:36Z")
Here’s a home test for about $16. > **[Amazon.com: Blood Type Kit - Also Includes: 1 Eldoncard, 1 Lancet, Gauze,...](https://www.amazon.com/Blood-Type-Kit-Eldoncard-Micropipette/dp/B000FSOCR4)** > > Easy, Self-testing Blood Type Kit - Everything you need to discover your blood type and rhesus factor in the comfort of your own home - pain free.This affordable kit comes complete with everything you need, including instructions, finger lancet and... > [@CairoCarol](#): > > If you don’t mind me riding on the coattails of this thread, can I ask knowledgeable Dopers if it possible to know your blood type if you know that of both parents? My husband and I are both A+. Does this mean our son must be too, or are there other possibilities? He’s either A or O. Check [this](http://www.biology.arizona.edu/Human_Bio/problem_sets/blood_types/inherited.html) out. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [February 20, 2009, 7:52am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/6 "2009-02-20T07:52:49Z")
Hey, good question. I have no idea what my blood type is either. I wonder how many people do in fact know this? ---
**Author:** ![Oakminster](https://avatars.discourse-cdn.com/v4/letter/o/77aa72/32.png) [@Oakminster](https://boards.straightdope.com/u/Oakminster)\ **Post date:** [February 20, 2009, 7:54am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/7 "2009-02-20T07:54:20Z")
Being on a google roll tonight…(explains blood type genetic stuff) [http://www.classkids.org/library/classqa/bloodtyp.htm](http://www.classkids.org/library/classqa/bloodtyp.htm) ---
**Author:** ![curlcoat](https://avatars.discourse-cdn.com/v4/letter/c/ea5d25/32.png) [@curlcoat](https://boards.straightdope.com/u/curlcoat)\ **Post date:** [February 20, 2009, 8:08am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/8 "2009-02-20T08:08:05Z")
> [@x-ray\_vision](#): > > Join the military and then read your ID card. I’m a little old (51) and not exactly in working order 😃 ---
**Author:** ![curlcoat](https://avatars.discourse-cdn.com/v4/letter/c/ea5d25/32.png) [@curlcoat](https://boards.straightdope.com/u/curlcoat)\ **Post date:** [February 20, 2009, 8:10am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/9 "2009-02-20T08:10:03Z")
> [@Oakminster](#): > > It’s probably listed in your medical records if you have any. Might be listed on your birth certificate…or your mother may know, if she’s available. I remember doing a blood typing excercise in high school biology years ago…maybe there are kits available online? Not in my records or on my birth certificate and mother not available. > [@](#): > > Yup..found via google, so buyer beware, but: > > [http://www.healthhometest.com/index.php](http://www.healthhometest.com/index.php) Wow, look at all of that! Thanks! ---
**Author:** ![curlcoat](https://avatars.discourse-cdn.com/v4/letter/c/ea5d25/32.png) [@curlcoat](https://boards.straightdope.com/u/curlcoat)\ **Post date:** [February 20, 2009, 8:11am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/10 "2009-02-20T08:11:59Z")
> [@x-ray\_vision](#): > > Here’s a home test for about $16. > [Amazon.com: Blood Type Kit - Also Includes: 1 Eldoncard, 1 Lancet, Gauze, Alcohol Wipe, Micropipette : Health & Household](http://www.amazon.com/Blood-Eldoncard-Determine-blood-minutes/dp/B000G33TM2) Huh, with all these choices, I wonder if a pharmacy would carry this? ---
**Author:** ![curlcoat](https://avatars.discourse-cdn.com/v4/letter/c/ea5d25/32.png) [@curlcoat](https://boards.straightdope.com/u/curlcoat)\ **Post date:** [February 20, 2009, 8:13am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/11 "2009-02-20T08:13:02Z")
> [@Leaffan](#): > > Hey, good question. I have no idea what my blood type is either. > > I wonder how many people do in fact know this? My husband does, but he is naturalized so that might be why. ---
**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\ **Post date:** [February 20, 2009, 8:19am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/12 "2009-02-20T08:19:05Z")
> [@curlcoat](#): > > Huh, with all these choices, I wonder if a pharmacy would carry this? I just checked some of the major pharmacies websites and nothing showed up, so I doubt you’ll find the test at your neighborhood pharmacy. It’s probably not an item requested enough to bother stocking. ---
**Author:** ![jabiru](https://avatars.discourse-cdn.com/v4/letter/j/bbce88/32.png) [@jabiru](https://boards.straightdope.com/u/jabiru)\ **Post date:** [February 20, 2009, 8:50am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/13 "2009-02-20T08:50:50Z")
Become a blood donor. ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [February 20, 2009, 9:24am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/14 "2009-02-20T09:24:12Z")
The OP states that he can’t, due to clotting. I’ve had the blood clot up in the needle before the bag was full a time or two. Now I drink a lot of water the day or two before I donate. I can’t guarantee results, but so far it’s worked for me. I’m O neg and the blood bank is always after me. While the A+A=O question has been answered, the positive and negative question hasn’t been addressed. Rh negative is recessive, therefore people with positive blood can produce children with negative blood. So two A positives can have the following children: A+ , A- , O+, or O-. Apologies if I missed a link that mentioned that. ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [February 20, 2009, 9:58am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/15 "2009-02-20T09:58:42Z")
In Spain it’s the kind of test that’s done in some pharmacies (generally a pharmacy that checks for glucose will check cholesterol and blood type as well). Maybe there’s some in yoru area which offer that kind of service? ---
**Author:** ![GuanoLad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guanolad/32/42_2.png) [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)\ **Post date:** [February 20, 2009, 10:21am UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/16 "2009-02-20T10:21:22Z")
I’m AB+ Sort of rare-ish, and kind of inverse-universal. I can handle any type of blood, but only others with AB+ can have my blood. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [February 20, 2009, 1:31pm UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/17 "2009-02-20T13:31:04Z")
Other than for blood donor purposes, where the notice goes out calling for “O” donors or similar, it’s not all that useful to know one’s blood type. It’s not a test we even run on 99.9% of our patients in a primary care setting, anyway. If one needs a transfusion, blood typing and many, many other more sophisticated compatibility tests will be run to figure out what type of blood product to give the person at that particular time. If you must know your type, go donate blood. You’ll get a nice card with your type and your rh factor on it. ---
**Author:** ![chrisk](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@chrisk](https://boards.straightdope.com/u/chrisk)\ **Post date:** [February 20, 2009, 1:42pm UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/18 "2009-02-20T13:42:37Z")
> [@GuanoLad](#): > > I’m AB+ > > Sort of rare-ish, and kind of inverse-universal. I can handle any type of blood, but only others with AB+ can have my blood. That would be ‘universal recipient’ I believe. O negative is properly ‘universal donor.’ There’s no truly universal blood type, just those two extremes, so you’re not inverted. Just… bloody selfish? 😉 ---
**Author:** ![Solfy](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@Solfy](https://boards.straightdope.com/u/Solfy)\ **Post date:** [February 20, 2009, 3:25pm UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/19 "2009-02-20T15:25:54Z")
I don’t think blood typing is always standard procedure for new babies. Or if it’s standard, it’s not required. It wasn’t on any of the paperwork for my daughters (both born outside hospitals), so I don’t know their blood type(s). My husband doesn’t know his, although there’s a record of it somewhere in his medical files since he’s received transfusions, so I can’t even narrow it down. When my brother was born he was typed, apparently part of protocol. I remember because his blood type is not that of either of our parents, but the nurse was quick to explain that this is totally normal don’t worry blah blah blah. It seems some parents get very upset and start suspecting parentage when the types don’t match up. ---
**Author:** ![BrotherCadfael](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@BrotherCadfael](https://boards.straightdope.com/u/BrotherCadfael)\ **Post date:** [February 20, 2009, 6:17pm UTC](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692/20 "2009-02-20T18:17:28Z")
I once asked my doc the same question. He advised me to go to the Red Cross, give blood, and then look at the donor card mailed to me a couple of weeks later. I think he was just promoting blood donation. [Next page](https://boards.straightdope.com/t/how-do-i-find-out-my-blood-type/486692.md?page=2)