Blood pressure is the force exerted by circulating blood against the walls of blood vessels, particularly the arteries. It is measured in millimeters of mercury (mmHg) and consists of two values: systolic pressure and diastolic pressure. Systolic pressure represents the force when the heart contracts and pumps blood into the arteries, while diastolic pressure represents the force when the heart is at rest between beats. Blood pressure is an important indicator of cardiovascular health and can be influenced by various factors such as age, genetics, lifestyle, and underlying medical conditions.