Your blood type — A, B, AB, or O — is more than a detail on a medical form. Research has associated each of the four major blood groups with distinct susceptibilities to serious conditions, ranging from cardiovascular disease and cognitive decline to gastric cancer and ulcers.
In brief
- —Blood types A, B and AB linked to higher heart attack risk
- —AB type individuals 82% more likely to develop dementia-related memory issues
- —Type O carries greater ulcer risk despite lower cancer susceptibility
How the ABO system classifies blood — and why a mismatch can be fatal
The ABO blood group system, developed by Dr. Karl Landsteiner, divides human blood into four types — A, B, AB, and O — based on specific proteins called antigens present in red blood cells. A second layer of classification comes from the Rh factor: if the Rh antigen is present, the blood is Rh positive; if absent, Rh negative.
