Aspirin can increased the rate of gastrointestinal (GI) bleeding by 22% (bleeding in the gut), and the risk of GI bleeding that required a transfusion by 40%. There was a 32% increase in peptic ulcers, and 6% of the 40,000 participants found blood in the urine. Easy bruising increased by 40%, and 16% of women experienced nose bleeds. The smokers in this study had a 30% higher risk of all major cardiovascular events while on the aspirin therapy. It had no impact on preventing cancer, and increased the risk of hemorrhagic stroke (bleeding in the brain) by 24%. Did not reduce the risk of heart attacks of any type.