Interpreting Your Blood Pressure
What does the reading we receive from a medical professional mean? Often we don’t know what this number represents, or even the actual reading, we are simply told our blood pressure is high, low, or nothing to be concerned about, but seldom are we told what it represents, or why it is important to monitor. Your blood pressure is the force created by the pumping of the heart as it moves blood from its lower left chamber out into the arteries of your body. If your blood pressure reading is high this means the heart is working too hard and the force it has to exert will cause a stressor on your whole body. If the blood vessels in your body are constricted, this will increase your blood pressure. Your blood pressure will fluctuate with every heartbeat; as well anxiety levels, physical activity, the time of day, your diet, and many other factors. Due to all these factors that will influence your reading, it is important to have your blood pressure checked on a regular basis in order to get an accurate reading of what is normal for your body.
To Understand What The Number Mean, Let’s Look at an Example
120/80 (which is the optimal blood pressure reading)
The 120 in this reading represents what is called the Systolic reading, it indicates the pressure in mmHg (millimeters of mercury) which the blood exerts against the aorta as the heart Contracts. The systolic pressure is influenced by the stroke volume of the heart, the speed of ejection, and the amount of elasticity in the walls of the blood vessels themselves. If the stroke volume or speed of flow increases, this will result in an increase in the BP, also if the aorta is less elastic or the blood meets increased peripheral resistance.
The 80 in the above reading represents what is called the Diastolic reading, it indicates the pressure in mmHg (millimeters of mercury) which the blood exerts against the arteries as the heart Relaxes. The diastolic pressure is influenced by the elastic qualities of the blood vessels, the functioning of the aortic valve (preventing back flow of blood back into the heart), as well as peripheral resistance.
Therefore an individual’s blood pressure is primarily based on a person’s
- Stroke volume: amount of blood ejected into the aorta with a single contraction
- Heart rate: number of contractions per minute
- Peripheral resistance: the amount of resistance met by the blood as it enters the arteries
How Does High Blood Pressure Do Damage?
The body can tolerate changes which happen with elevated blood pressure before any signs or symptoms are detected. This is why hypertension is often given the name “the silent killer”, because the transition from health to illness is often asymptomatic (“without” symptoms). Sometimes an individual will experience headaches, dizziness, or shortness of breath to start and gradually over time more serious complications will arise. The heart is essentially getting an “extra” workout. The muscle of the heart over time will enlarge and require more oxygen, as does any muscle in the body that is overworked. At first the body can adapt to these extra demands but over time the continuous stress may lead to heart failure as the overall functioning of the heart is challenged.
The extra push which is exerted by the heart as it pumps the blood out against the arterial walls can also lead to hardening and narrowing of the arteries.
Prolonged high blood pressure, or hypertension, will increase the risk of:
- Stroke (rupture or obstruction of blood vessels in the brain)
- Heart attack (presence of blood clots or narrowing of the arteries that supply the heart)
- Congestive heart failure
- Arteriosclerosis (thickening of the arterial walls and a loss of elasticity)
- Atherosclerosis (a form of arteriosclerosis which affects the medium and large arteries and can lead to a reduction or obstruction of blood flow and hardening of the arteries)
- Peripheral vascular disease (affecting the blood vessels of the limbs)
- Pulmonary congestion (congestion in the lungs due to thickening in the chambers on the left side of the heart)
- Kidney failure.
These are a Few Things to be Aware of in Understanding the Importance of Monitoring Your Blood Pressure
Lifestyle Risk Factors
- Smoking – this causes plaque to build up in the arteries. Smokers are 2 times more likely to have a heart attack or stroke than non-smokers.
- Stress and anxiety, which have a cumulative effect. Long-term stress will chronically elevate blood pressure as it puts the body in the “flight or flight” (sympathetic nervous system) mode which causes constriction of the arteries. One of the many reasons it is so important to take time out of our busy and stressful lifestyles to relax and break this stress cycle.
- Oral contraceptives can contribute to high BP
- Excessive alcohol intake
- Men over 45 and women over 35 are at a higher risk for developing hypertension
- Caffeine, cough/cold medicines and pain relievers will also temporarily elevate blood pressure.
Interpreting the Readings