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Sharp Health News

How important is it to know your blood type?

Oct. 26, 2017

How important is it to know your blood type?

Are you A, B or O? Positive or negative? Many people do not know or remember their own blood type — but how important is it to know this information?

According to Dr. Kristen Rice, a hematology and oncology doctor affiliated with Sharp Community Medical Group, if you need to receive a blood transfusion, the blood bank will always check your blood type and perform a crossmatch to confirm compatibility.

“A crossmatch is where they mix a sample of your blood with a sample of the blood to be given to you to make sure they are compatible,” says Dr. Rice. “While not critical, knowing your blood type is a good fact to know. And now with technology like our smartphones, there is an easy way to store this medical information — along with allergies and emergency contacts — for reference if you are ever found unconscious.”

If you are in a serious accident and need blood right away — and there is no time to wait for the crossmatch process — the hospital will likely give you O-negative blood until they have time to confirm your type. O-negative blood is the most likely to be compatible with other blood types, including A-positive, A-negative, B-positive, B-negative, AB-positive, AB-negative and O-positive.

When is it helpful to know your blood type?

  • When traveling — especially to countries with a low blood supply. It could be a lifesaving piece of information to know your blood type. Make sure to let your travel companions know as well, in case you become unconscious.

  • When donating blood. Dr. Rice explains that for most healthy adults, donating blood is a simple process that allows you to give the gift of life.

According to the San Diego Blood Bank, the following is an approximate distribution of blood types in the U.S. blood donor population.

O-positive38 percent
O-negative7 percent
A-positive34 percent
A-negative6 percent
B-positive9 percent
B-negative2 percent
AB-positive3 percent
AB-negative1 percent

What does your blood type mean?
“O-negative blood is the universal donor,” says Dr. Rice. “Hospitals can give it to anybody in an emergency, so it is good to have a lot of it on hand.”

“O-positive and A-positive are the most common types, so there is a lot of demand for these,” says Rice. “However, even if you have a rare type, you should consider donating blood because your type may be hard to come by.”

Blood banks provide blood for more than just car accidents. Blood transfusions help:

  • Patients who have lost a lot of blood due to a severe accident or major surgery
  • Patients with cancer who are undergoing chemotherapy, especially those with blood cancers like leukemia
  • Patients with bone marrow disorders like aplastic anemia, who can’t manufacture enough of their own blood

Donating blood is vitally important because blood transfusions save lives. Sharp HealthCare is proud to partner with the San Diego Blood Bank in encouraging residents to give the gift of life. Find eligibility guidelines and donation sites on the San Diego Blood Bank website.

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