1. The most direct method through medical testing is to go to a hospital or blood donation station for blood type testing. Medical staff will collect your blood sample and determine your blood type through standard blood type testing methods such as agglutination reaction.
2. View past medical records: If you have had surgery, blood donation, or medical examinations that require blood type information before, you can view these medical records to obtain your blood type information.
3. Genetic inference (not absolutely accurate): Knowing the blood types of both your parents can to some extent infer your possible range of blood types, but this is not absolutely accurate due to complex situations such as genetic mutations.