Healthwise

Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein.

Blood type

Human blood is typed according to whether certain markers, called antigens, are present on the surface of red blood cells. The ABO system classifies blood as type A, B, AB, or O based on the presence or absence of the A and B antigens; the Rh system classifies blood as negative or positive based on the presence or absence of the Rh antigen (Rh factor).

If red blood cells have:

  • The A antigen, they are type A blood.
  • The B antigen, they are type B blood.
  • Both the A and B antigens, they are type AB blood.
  • Neither A nor B antigens, they are type O blood.

Rh blood typing determines the presence (+) or absence (–) of the Rh factor. If red blood cells:

  • Have the Rh antigen, they are Rh-positive.
  • Do not have the Rh antigen, they are Rh-negative.

Due to the threat of the COVID-19 (Coronavirus), we are taking precautionary measures to protect our staff and patients. We are implementing a temporary NO VISITOR policy at this time. Only patients or patients and their guardians will be allowed into the office. Please note, this is not to inconvenience anyone! The virus is a very real threat and it is essential that we stay healthy in order to provide needed care for our patients. If you are sick, we ask that you CALL the office to speak with a nurse before you come in. The nurse will provide specific instructions for you. Please DO NOT enter the office if you are sick (upper respiratory symptoms, fever, cough, or flu like symptoms). We are closely monitoring the situation and will update you as circumstances change. Thank you for your understanding!!