Depends on how you look at it. O negative is the universal donor therefore the highest demand for trauma and critical patients who will not survive waiting for a lab to type/cross a blood sample. AB positive is the universal receiver thus able to be transfused with any donor's blood.
ab
type o is compatible with all blood types
You are compatible with your own blood type and type O, unless you are type AB, then you are compatible with A, B, AB and O. It's important to have compatible blood types especially during pregnancy.
O+ is compatible with all Blood types. A+/- B+/- O
Type O negative should be used for woman of child-bearing age when given urgently to avoid complications of an unknown RH negative pregnancy. Cross matching is preferred for all patient whan the situation is not for resuscitation.
Yes there is a universal blood type. O negative. It is extremely rare, the rarest of all blood types, however it can be used in patients with all types of blood types.
It all depends on their blood type. It may compatible even if they are unrelated.
When the body encounters types of blood it is not familiar with, it makes antibodies to attack it. That's why O- is the universal donor. O means it has neither A or B components, and the negative means it does not have specific receptor proteins on it. That's also why someone AB+ can have any type of blood, because the body is used to A components, B components, and receptor proteins.
The blood type that is theoretically considered the universal donor is type O. Type O blood does not have any antigens, therefore it is compatible with any blood type.
O- is compatible with donating to all blood types. AB+ is compatible with receiving from all blood types. All other blood types are on their own with compatibility.
It is not true that patients who are Rh positive can't get HIV. Patients with all blood types should take steps to prevent HIV.
Put simply there is no "best" blood type. The blood type a person has is specific to that person. However, in emergencies O Neg is compatible with all people. That is to say it will keep someone alive short term who is losing blood.