The measurement of blood pressure without further specification usually refers to the systemic arterial pressure, defined as the pressure exerted by circulating blood upon the walls of blood vessels. Blood pressure in the arteries is much higher than in the veins, in part due to receiving blood from the heart after contraction, but also due to their contractile capacity.
The tunica media of arteries is thickened compared to veins, with smoother muscle fibers and elastic tissue. Together, these generate of elastic recoil and blood vessel contraction, allowing for the maintenance of a higher pressure. Typical Tools of Auscultatory Measurement : Shown here are a stethoscope and a sphygmomanometer, used for ascultatory measurement.
While average values for arterial pressure could be computed for any given population, there is extensive variation from person to person and even from minute to minute for an individual. Additionally, the average arterial pressure of a given population has only a questionable correlation with its general health.
Normal values fluctuate through the hour cycle, with the highest readings in the afternoons and lowest readings at night. Changes in Arterial Pressure : Arterial pressures changes across the cardiac cycle. In the past, hypertension was only diagnosed if secondary signs of high arterial pressure were present along with a prolonged high systolic pressure reading over several visits. Hypotension is typically diagnosed only if noticeable symptoms are present.
Clinical trials demonstrate that people who maintain arterial pressures at the low end of these ranges have much better long-term cardiovascular health. The principal medical debate concerns the aggressiveness and relative value of methods used to lower pressures into this range for those with high blood pressure. Elevations more commonly seen in older people, though often considered normal, are associated with increased morbidity and mortality.
Arterial hypertension can be an indicator of other problems and may have long-term adverse effects. Sometimes it can be an acute problem, such as a hypertensive emergency. All levels of arterial pressure put mechanical stress on the arterial walls. Higher pressures increase heart workload and progression of unhealthy tissue growth atheroma that develops within the walls of arteries. The higher the pressure, the more stress that is present, the more the atheroma tends to progress, and the more heart muscle may thicken, enlarge, and weaken over time.
Persistent hypertension is one of the risk factors for strokes, heart attacks, heart failure, and arterial aneurysms, and is the leading cause of chronic renal failure. Even moderate elevation of arterial pressure leads to shortened life expectancy.
In the past, most attention was paid to diastolic pressure, but now we know that both high systolic pressure and high pulse pressure the numerical difference between systolic and diastolic pressures are also risk factors for disease. In some cases, a decrease in excessive diastolic pressure can actually increase risk, probably due to the increased difference between systolic and diastolic pressures.
Venous pressure is the vascular pressure in a vein or the atria of the heart, and is much lower than arterial pressure. Blood pressure generally refers to the arterial pressure in the systemic circulation. However, measurement of pressures in the human venous system and the pulmonary vessels play an important role in intensive care medicine and are physiologically important in ensuring proper return of blood to the heart, maintaining flow in the closed circulatory system.
The Human Venous System : Veins from the Latin vena are blood vessels that carry blood towards the heart. Veins differ from arteries in structure and function; arteries are more muscular than veins, while veins are often closer to the skin and contain valves to help keep blood flowing toward the heart.
Venous pressure is the vascular pressure in a vein or the atria of the heart. It is much lower than arterial pressure, with common values of 5 mmHg in the right atrium and 8 mmHg in the left atrium. Typically, more attention is given to systolic blood pressure the first number as a major risk factor for cardiovascular disease for people over In most people, systolic blood pressure rises steadily with age due to the increasing stiffness of large arteries, long-term buildup of plaque and an increased incidence of cardiac and vascular disease.
However, either an elevated systolic or an elevated diastolic blood pressure reading may be used to make a diagnosis of high blood pressure. According to recent studies, the risk of death from ischemic heart disease and stroke doubles with every 20 mm Hg systolic or 10 mm Hg diastolic increase among people from age 40 to The abbreviation mm Hg means millimeters of mercury.
Mercury was used in the first accurate pressure gauges and is still used in medicine today as the standard unit of measurement for pressure. While both are indications of health, blood pressure and heart rate pulse are two separate measurements. Learn more about the difference between blood pressure and heart rate. Great job! Your blood pressure is normal. To keep your readings in this range, stick with heart-healthy habits like following a balanced diet and getting regular exercise.
However, your numbers fall within the Elevated category, making you more likely to develop high blood pressure unless you take action to control it. Ready to make some small changes that have big impacts? Healthy lifestyle choices are a great place to start. You are in the first stage of hypertension , but there are actions you can take to get your blood pressure under control.
Your doctor will speak to you about small changes that can make a big difference and other BP Raisers. It looks like you have Stage 2 Hypertension. Your BP falls within the Hypertensive crisis category and requires immediate attention. This occurs because of reflective waves from vessel branching, and from decreased arterial compliance increased vessel stiffness as the pressure pulse travels from the aorta into systemic arteries. There is only a small decline in mean arterial pressure as the pressure pulse travels down distributing arteries due to the relatively low resistance of large distributing arteries.
Learn what determines systolic and diastolic pressures. Cardiovascular Physiology Concepts Richard E. Klabunde, PhD. Klabunde, all rights reserved Web Design by Jimp Studio.
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