20 Facts About Blood pressure

Blood pressure is the pressure of circulating blood against the walls of blood vessels.

Blood pressure is usually expressed in terms of the systolic pressure over diastolic pressure in the cardiac cycle.

Blood pressure is one of the vital signs—together with respiratory rate, heart rate, oxygen saturation, and body temperature—that healthcare professionals use in evaluating a patient's health.

Blood pressure is influenced by cardiac output, systemic vascular resistance, blood volume, arterial stiffness and varies depending of patient's situation, emotional state, activity, and relative health or disease state.

Blood pressure that is too low is called hypotension, pressure that is consistently too high is called hypertension, and normal pressure is called normotension.

In practice blood pressure is considered too low only if symptoms are present.

Reference blood pressure values have been developed for children in different countries, based on the distribution of blood pressure in children of these countries.

An age-related rise in blood pressure is not considered healthy and is not observed in some isolated unacculturated communities.

Blood pressure generally refers to the arterial pressure in the systemic circulation.

Venous Blood pressure is the vascular Blood pressure in a vein or in the atria of the heart.

The remaining pressure measured after cessation of the heart beat and redistribution of blood throughout the circulation is termed the mean systemic pressure or mean circulatory filling pressure; typically this is proximally ~7mm Hg.

Large fall in blood pressure upon standing is termed orthostatic hypotension and represents a failure of the body to compensate for the effect of gravity on the circulation.

Variations in pressure that are significantly greater than the norm are associated with increased risk of cardiovascular disease brain small vessel disease, and dementia independent of the average blood pressure level.

Older individuals and those who had received blood pressure medications are more likely to exhibit larger fluctuations in pressure, and there is some evidence that different antihypertensive agents have different effects on blood pressure variability; whether these differences translate to benefits in outcome is uncertain.

However, blood pressure is regulated by neural regulation from the brain, as well as osmotic regulation from the kidney.

Pulse pressure is a consequence of the pulsatile nature of the cardiac output, i e the heartbeat.

The magnitude of the pulse Blood pressure is usually attributed to the interaction of the stroke volume of the heart, the compliance of the arterial system—largely attributable to the aorta and large elastic arteries—and the resistance to flow in the arterial tree.

Endogenous, homeostatic regulation of arterial Blood pressure is not completely understood, but the following mechanisms of regulating arterial Blood pressure have been well-characterized:.

When blood pressure falls many physiological cascades commence in order to return the blood pressure to a more appropriate level.

Arterial pressure is most commonly measured via a sphygmomanometer, which uses the height of a column of mercury, or an aneroid gauge, to reflect the blood pressure by auscultation.