Medically Reviewed By William C. Lloyd III, MD, FACS
— Written By Dan Amankwah
Updated on March 1, 2023
This article covers what factors determine blood type and how it affects health, as well as blood type diets, donation, transfusions, rare blood types, and statistics.
What is blood type?
Blood type is the immunologic identity of your blood. It
Experts commonly use the ABO and Rh systems to group blood types.
The ABO system puts blood types into four categories: A, B, AB, and O. The Rh system complements the ABO system by assigning a positive or negative sign to blood types.
Below is a breakdown of the ABO blood types:
- Type A: has A antigens on the red blood cell surface and anti-B antibodies in the plasma
- Type B: has B antigens on the red blood cell surface and anti-A antibodies in the plasma
- Type O: has both anti-A and anti-B antibodies on the surface, and both anti-A and anti-B antibodies in the plasma
- Type AB: has both A and B antigens on the surface, but no antibodies in the plasma
Depending on whether Rh factor is present or absent, a person’s blood type can be positive or negative. This means a person can typically have 1 of 8 different blood types:
- A-positive (A+)
- A-negative (A–)
- B-positive (B+)
- B-negative (B–)
- O-positive (O+)
- O-negative (O–)
- AB-positive (AB+)
- AB-negative (AB–)
The genes you inherit from your parents
The majority of people have an Rh-positive blood type. A+ is one of the most common blood types, accounting for around 1 in 3 blood types.
Learn about Rh factor.
Non-ABO blood types
Some blood types do not fall under the ABO group, due to different antigens. One such blood type is Rhnull or “golden blood.”
Rhnull is an
Learn more about rare blood types.
Why does blood type matter?
Your blood type can increase your risk of certain conditions and lower your risk of others. This is because the characteristics found in the genes responsible for the different blood types are linked to the likelihood of developing other medical conditions.
A
- Type A: This may increase a person’s risk of smallpox and Pseudomonas aeruginosa infection.
- Type B: This may raise the risk of gonorrhea, tuberculosis, E. coli, and other infections.
- Type AB: This may increase the risk of cognitive impairment, high blood pressure, and cardiovascular disease. AB may also raise your risk of smallpox, E. coli, and Salmonella infections.
- Type O: This may raise a person’s risk of cholera, plague, tuberculosis infections, and mumps.
Another
- Type A and AB: These may increase a person’s risk of heart attack, stroke, and blood clots in the veins.
- Type A: This may raise the risk of chronic hepatitis-B infection and pancreatic cancer.
- Type B: This may increase the risk of ovarian cancer.
- Type O: This may increase a person’s protection against falciparum malaria. However, it may also increase the severity of Vibrio cholerae infection, the pathogen that causes cholera.
- Non-O blood groups: These types may increase the risk of cerebral venous thrombosis, a condition that causes a blood clot to form in one of your brain’s larger veins.
A 2021 study also indicates that Type A and Type AB could raise a person’s risk of COVID-19, while Type O could reduce the risk.
However, having a certain blood type does not necessarily mean that you will develop a condition more commonly associated with that blood type. If you have any concerns, you may wish to contact your doctor about ways to reduce your risk of these conditions.
Learn more about how blood types can affect your health.
Donation and transfusions
It is
Here is a summary of how doctors match different blood types:
- People with Type O can donate blood to people of all blood types.
- People with Type AB can accept blood from all donors.
- People with Type A can only receive Type A or Type O.
- People with Type B can receive Type B or Type O.
The American Society of Hematology provides more blood type matching details as follows:
| Recipient blood type | Compatible donor blood type |
| A+ | A+, A–, O+, O– |
| A– | A–, O– |
| B+ | B+, B–, O+, O– |
| B– | B–, O– |
| AB+ | matches with all blood types |
| AB– | AB–, A–, B–, O– |
| O+ | O+, O– |
| O– | O– |
Blood donation is important and can save lives. According to the UK’s National Health Service, you can donate blood if you:
- are healthy
- weigh at least 50 kg (about 110.2 lb)
- are 17–66 years old
- are over age 70 and have given blood in the last 2 years
Learn about blood transfusions.
Can blood type influence personality?
Some sources claim that a person’s blood group could influence their personality. The accuracy of this hypothesis is unclear, but one
The study recruited 1,427 Japanese people and had them take a blood typing test and a character inventory. The results of the tests suggested that certain ABO-blood-related genes could affect personality traits.
Further research to determine the exact relationship between blood groups and personality is necessary.
What is a blood type diet?
A naturopathic physician named Dr. Peter J. D’Adamo advocates a “blood type diet.” It is a dietary plan based on the ABO blood group.
D’Adamo claims that the foods you eat can interact with your blood type. He also provides a list of foods he claims are ideal for each blood group.
According to the blood type diet, people with Type A blood should consume vegetarian foods. These include:
- fruits and vegetables
- legumes
- whole grains
- nuts
- seeds
There is currently
Learn more about the blood type diet and Type O+ blood.
Blood type stats
The following are blood type stats from the American Red Cross:
- 1 in 3 people has Type A+ blood.
- Around 37% of the population have Type O+, making it the most common type.
- Approximately 45% of Caucasian people, 51% of African American people, and 57% of Hispanic people have Type O.
- Only 7% of the population has Type O– blood. However, O– blood is in the highest demand because it is the most preferred blood type for emergencies.
Other frequently asked questions
Here are other questions people have asked about Type A+ blood.
Is blood type A-positive rare?
Type A+ is one of the most common blood types. Around 1 in 3 people have Type A+ blood.
Is blood type A-positive good?
Type A+ is one of the most common blood types, and its blood transfusion availability is relatively good. If you have Type A+ blood, you can receive A+, A–, O+, and O– blood types during a transfusion.
What is the healthiest blood type?
Studies suggest that Type O may reduce your risk of cardiovascular disease. However, additional research is necessary to determine if it is the healthiest blood type and what effect blood types have on health.
Summary
Type A+ blood is a blood type with type A antigens and a positive Rh factor. It is one of the most common blood types.
Your blood type may increase your risk of certain conditions. For example, you could be at an increased risk of smallpox if you have Type A.
It is critical to receive a compatible blood type during a blood transfusion. Receiving an incompatible blood type can cause your body to produce antibodies to destroy the donor blood cells.
Consider contacting your doctor or taking a test to find out your blood type.
