1. Blood Clots
Danish scientists have identified a link between those with AB blood type and deep vein thrombosis (DVT). DVTs are blood clots in the lower legs that can be life threatening if they break free and travel to the heart or lungs. Those with A or B type blood are at a slightly higher risk.

2. Heart Disease
The risk of coronary heart disease may also be linked to blood types. And AB was found to have a much higher risk than O, A and B were both slightly higher than O.