Definition of Blood Pressure
Blood pressure is the force exerted by circulating blood against the walls of arteries as the heart pumps it throughout the body. It is typically measured in millimeters of mercury (mmHg) and expressed as two numbers: systolic pressure, the higher value when the heart contracts, and diastolic pressure, the lower value when the heart relaxes between beats. This measurement reflects the efficiency of blood flow to organs and tissues.
Key Components of Blood Pressure
Blood pressure depends on several factors, including cardiac output (the amount of blood pumped by the heart per minute), peripheral resistance (the resistance to blood flow in arteries), and blood volume. Systolic pressure occurs during ventricular contraction, pushing blood into arteries, while diastolic pressure represents the resting phase. Normal ranges are around 120/80 mmHg for adults, but values can vary based on age, fitness, and health conditions.
Practical Example: Interpreting Blood Pressure Readings
Consider a reading of 140/90 mmHg: the systolic value of 140 indicates elevated pressure during heartbeats, potentially signaling hypertension, while the diastolic 90 suggests increased resting pressure. In contrast, a healthy athlete might have 110/70 mmHg, showing efficient circulation. Monitoring these values helps track changes, such as how exercise lowers pressure by improving vessel flexibility.
Importance of Blood Pressure in Health
Maintaining optimal blood pressure is crucial for delivering oxygen and nutrients to organs while preventing damage to blood vessels. High blood pressure (hypertension) strains the heart and arteries, increasing risks of heart disease, stroke, and kidney failure. Low blood pressure (hypotension) can cause dizziness or fainting due to inadequate organ perfusion. Regular monitoring and management through lifestyle or medication support overall cardiovascular health and longevity.