What's Your Type and Why Does it Matter?

Thirty-three percent of Americans don’t know their blood type. And while it may seem like that information isn’t important in your day-to-day life, research is beginning to connect blood type to a person’s risk of developing certain medical conditions.

To understand how there may be a connection, you need to know how blood type is determined. It’s based on the presence or absence of two things:

1. Antibodies and antigens. The letter in your blood type indicates the ABO antigens and antibodies found in your blood and plasma. A blood types have A antigens on the red blood cells with anti-B antibodies in plasma. B types have B antigens and anti-A antibodies. O types have no antigens at all, but both A and B antibodies in the blood, and AB blood types have both A and B antigens without any antibodies.
2. RhD factor. The positive or negative sign in your blood type indicates whether or not you have the RhD antigen on your red blood cells. Positive blood types have RhD while negative types don’t.

Your blood type is important for a lot of reasons. The most obvious one is that if you’re ever hurt and need supplemental blood, getting the wrong type could be life threatening. If your body produces antibodies against the antigens in the blood you receive, your body will destroy the new blood cells and cause a reaction. It’s also important during pregnancy. If a pregnant mother is Rh negative and her baby is Rh positive, she’ll need to closely monitor her antibody levels and possibly have an injection that will prevent her from producing Rh antibodies during pregnancy.

Blood type is also correlated with other health conditions, though researchers are still studying the connections between some of these conditions and blood type. Below are some of the risks associated with each blood type, though it’s important to keep in mind that blood type is just one factor that contributes to your health risk. There are many other environmental and genetic factors that could impact your likelihood of developing a particular condition.

Blood type A

• More likely to develop memory and cognition problems
• Higher risk of developing Type 2 diabetes
• Higher risk of blood clots
• Higher risk of stomach cancer
• Increased risk of high cholesterol
• Higher levels of stress hormones

Type B

• More likely to develop memory and cognition problems
• Highest risk of developing Type 2 diabetes
• Higher risk of heart disease
• Higher risk for rheumatoid diseases
• Lower risk of kidney stones

Type 0

• More likely to suffer from fertility issues
• Higher risk of Hashimoto’s thyroid disease

• Increased risk of peptic ulcers
• Lower risk of pancreatic cancer
• Lower risk of cardiovascular disease
• Lower risk for certain strains of malaria

If you don’t know your blood type, ask your doctor for a quick test at your next checkup or consider donating to a blood center. You’ll receive a report that includes your blood type with your donation.

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Christopher Lee, MD
Family Medicine
Baton Rouge General Physicians - Shenandoah
(225) 752-4530