Video narration
Blood pressure is the force of blood pushing against the walls of your arteries. Your heart is the pump: with each beat, it sends blood out through arteries to deliver oxygen and nutrients all around your body. A blood pressure reading shows two numbers. The top number is systolic pressure—how much pressure is in the arteries when the heart squeezes and pushes blood forward. The bottom number is diastolic pressure—the pressure when the heart relaxes and refills between beats. Blood pressure isn’t “good” or “bad” by itself; you need enough pressure to keep blood moving. And it naturally changes. It rises during exercise or stress, and it can shift with sleep, hydration, and overall health. Arteries also matter: flexible, open vessels help absorb the pressure, while tighter or stiffer vessels make pressure climb. In short: heart pumping plus vessel resistance equals your blood pressure.