Both systolic and diastolic blood pressure are important because they provide different information about your cardiovascular health.
Systolic blood pressure (the top number) indicates the amount of pressure in your arteries when your heart is pumping blood. High systolic blood pressure is a major risk factor for cardiovascular disease, stroke, and kidney disease. In fact, according to medical guidelines, systolic blood pressure is considered a more important cardiovascular risk factor than diastolic blood pressure.
Diastolic blood pressure (the bottom number) indicates the amount of pressure in your arteries when your heart is resting between beats. Low diastolic blood pressure can be a sign of underlying health conditions such as heart failure or hypovolemia (low blood volume). However, in general, high systolic blood pressure is a more important risk factor for cardiovascular disease than low diastolic blood pressure.
Overall, it is important to monitor both systolic and diastolic blood pressure, as well as other cardiovascular risk factors, to maintain optimal cardiovascular health.