Short answer
For red cells, O negative can give to every group and AB positive can receive from every group. Otherwise a patient can receive from their own group and from O, and Rh positive patients can also receive Rh negative blood. In practice most patients receive their own group, and the hospital always tests and cross-matches before a transfusion.
The compatibility chart for red cells
Find the patient’s group in the first column. The second column shows whose red cells they can receive; the third shows who they can give to.
| Blood group | Can receive red cells from | Can give red cells to |
|---|---|---|
| O− | O− only | Everyone |
| O+ | O+, O− | O+, A+, B+, AB+ |
| A− | A−, O− | A+, A−, AB+, AB− |
| A+ | A+, A−, O+, O− | A+, AB+ |
| B− | B−, O− | B+, B−, AB+, AB− |
| B+ | B+, B−, O+, O− | B+, AB+ |
| AB− | AB−, A−, B−, O− | AB+, AB− |
| AB+ | Every group | AB+ only |
This chart is for red cells and whole blood. Plasma and platelets are matched differently, and the hospital blood bank always tests and cross-matches before any transfusion.
Which blood group can donate to all?
O negative. O negative red cells are safe for everyone to receive, which is why O negative is called the universal donor (NHS Blood and Transplant). At the other end, AB positive patients can receive red cells from any group, so AB positive is the universal recipient (Héma-Québec).
Common questions, answered
Who can donate blood to O+?
O positive and O negative donors only.
Can O positive donate to B positive?
Yes. O positive red cells can go to O+, A+, B+ and AB+ patients.
Can B positive donate to O positive?
No. An O positive patient cannot receive B red cells.
O negative can receive blood from whom?
Only O negative. That is why O negative patients and donors need each other most.
Who can give to A+ and B+?
A+ patients can receive from A+, A−, O+ and O−. B+ patients can receive from B+, B−, O+ and O−.
Need blood in Quetta?
Tell us first, then call the donors shown to you.
Give the patient’s blood group, the hospital and your number. Khidmat shows you registered donors whose blood the patient can receive, the patient’s own group first, offered in turn.
How rare is O negative in Pakistan?
Rh negative groups (O−, A−, B− and AB−) are uncommon in Pakistan. A 2019 study of 3,521 people in Karachi found 8.9 percent were Rh negative, and studies across Pakistan have found between 5.4 and 10.7 percent (Journal of the Pakistan Medical Association). O negative is one part of that small share, so O negative donors are few, and they are asked for every emergency.
If you are O negative, registering as a donor matters more than for most groups, and so does resting between donations.
Own group first: how Khidmat matches
Most patients receive blood from a donor of their own group (Héma-Québec). Khidmat follows the same order. When someone asks for blood on the Blood Bank page, they see donors of the patient’s own group first, then donors of other groups whose red cells the patient can safely receive, each offered in turn. O negative donors are not called for every request just because they suit everyone.
Can you give?
Register once. We ask only when your blood can help.
You are contacted only when a patient who can receive your blood group needs blood, never within six months of your last donation, and your number is never published.
Questions people ask
Which blood group can donate to all?
O negative, for red cells. O negative red cells are safe for every group.
Which blood group can receive from all?
AB positive, for red cells.
Can a patient always receive O negative?
For red cells, O negative suits every group, but the hospital still tests and cross-matches each bag before giving it.
Is this chart the same for plasma?
No. Plasma is matched almost the other way round. Ask the hospital blood bank for plasma and platelets.
Sources
- Blood types, NHS Blood and Transplant
- Blood types, Héma-Québec
- Distribution pattern of ABO and Rhesus blood groups among different ethnic population of Karachi, Journal of the Pakistan Medical Association, 2019
