Onions can lower blood pressure because they contain a substance called prostaglandin A. This substance dilates blood vessels and reduces the viscosity of the blood. This substance can dilate blood vessels and reduce the viscosity of blood, which has the effect of lowering blood lipids and blood pressure, and can increase the blood flow in the coronary arteries, which can also indirectly prevent blood clots. It is rich in potassium and folic acid and other trace elements, which are all good for the human body. Usually eating onions can stimulate appetite, help digestion and prevent constipation, which is good for hypertension, but you cannot expect onions to lower blood pressure. If blood pressure is too high, it should be treated by medication, which is the root of treating hypertension. Usually in life, diet can play an auxiliary effect, but also to increase physical exercise, comprehensive pressure reduction.