Without some pressure in your vessels, your blood couldn't circulate through your body. And without circulating blood, your vital organs couldn't get the oxygen and food they need to keep working.
Blood pressure is important.
Your blood pressure doesn't stay the same. It varies from moment to moment as your heartbeat adjusts to meet your body's needs. For example, your blood pressure rises when you're exercising or excited, and drops when you're resting or asleep. Changes are normal. When your heart beats, it pumps blood through large blood vessels called arteries.