If your blood is A positive (A+), it means that your blood contains type-A antigens with the presence of a protein called the rhesus (Rh) factor. Antigens are markers on the surface of a blood cell.
According to the American Red Cross, this is one of the most common blood types.
Blood types are passed down genetically. If you have type A blood, your parents had one of the following possible combinations of blood types:
- AB and AB
- AB and B
- AB and A
- AB and O
- A and B
- A and A
- O and A
For example, both parents are type AB, or one parent is type AB and the other type B.
Parents with the following combinations of blood types couldn’t have a child with type A blood:
- B and B
- O and B
- O and O
While there is no scientific proof that blood types are associated with certain personality traits, it’s a persistent theory in Japanese culture known as “ketsuekigata.”
According to those who believe this theory, these are the personality traits associated with the A+ blood type:
“Eat Right for Your Type” is a best-selling book that suggests you can achieve your ideal weight and be healthier by choosing a diet based on your blood type. It was written in the 1960s and is still popular today.
The book suggests the following for diet for people with type A+ blood:
- Avoid meat.
- Avoid wheat, corn, kidney beans and dairy.
- Eat seafood, turkey and tofu.
- Eat fruit, vegetables and whole grains.
According to Harvard Medical School, there is no evidence that the diet works.
The ABO blood group system groups human blood into four main types:
The system is based on antigens that are either present or absent on the surface of a person’s red blood cells.
Because of compatibility issues between blood groups, it’s critical that appropriate donors are matched with a person who needs a blood transfusion:
- If you have type AB blood, you are a universal recipient and can receive blood from all donors.
- If you have type O blood, you are a universal donor and can donate blood to anyone.
- If you have type A blood, you can receive type A or type O blood.
- If you have type B blood, you can receive type B or type O blood.
If you mix blood from two people with wrong blood types, the antibodies in the blood of the person receiving the transfusion will fight the cells of the donor’s blood, resulting in a potentially fatal toxic reaction.
Above and beyond ABO blood typing, your blood will be classified by the presence or absence of a specific protein (rhesus factor):
- Rh positive (+)
- Rh negative (–)
The most common blood types are A+, A–, B+, B–, O+, O–, AB+, and AB–. The rarest of these is type AB–.
According to the American Red Cross, there are more than 600 other known antigens. Any of those antigens being present or absent creates rare blood groups — defined as lacking the antigens that 99 percent of people are positive for.
If you have type A+ blood, you have a relatively common blood type that you inherited from your parents.
Your blood type is a critical factor in determining a match in the event you need a blood transfusion. If you don’t know your blood type, tell your doctor you would like to be tested.