Key points from article :
Aspirin slows the ability of the blood to form clots, reducing the chances of heart attacks and strokes.
This also means it increases the risk of serious bleeding, which can be equally serious.
2.31 in every 1,000 people who had aspirin had a major bleed each year, compared to 1.64.
Risk reduction for cardiovascular events of similar magnitude to risk increase for major bleeding.
Meta-analysis of 13 trials with total of 164,225 participants by King's College London.
UK guidelines for preventive low-dose aspirin say only if your doctor has recommended it.
The study was published in Journal of the American Medical Association.
