Blood pressure (BP) is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs.
Hypertension is the term used to describe high blood pressure.
Blood pressure readings are usually given as two numbers -- for example, 120 over 80 (written as 120/80 mmHg). One or both of these numbers can be too high.
The top number is called the systolic blood pressure, and the bottom number is called the diastolic blood pressure.
Normal blood pressure is when your blood pressure is lower than 120/80 mmHg most of the time.
High blood pressure (hypertension) is when your blood pressure is 140/90 mmHg or above most of the time.
If your blood pressure numbers are 120/80 or higher, but below 140/90, it is called pre-hypertension.
Most of the time, no cause of high blood pressure is found. This is called essential hypertension.
Malignant hypertension is very high blood pressure that comes on suddenly and quickly. The lower (diastolic) blood pressure reading, which is normally around 80 mmHg, is often above 130 mmHg.
Hypertensive heart disease refers to heart problems that occur because of high blood pressure. These problems include:--
* Coronary artery disease
* Heart failure
* Thickening of the heart muscle
Hypertensive retinopathy is damage to theretina from high blood pressure. The retina is the layer of tissue at the back part of the eye. It changes light and images that enter the eye into nerve signals that are sent to the brain.
Renovascular hypertension is high blood pressure due to narrowing of the arteries that carry blood to the kidneys. This condition is also called renal artery stenosis.
Isolated systolic hypertension is defined as a systolic pressure that is above 140 mm Hg with a diastolic pressure that still is below 90.
Low blood pressure (hypotension) is blood pressure low enough to cause symptoms such as dizziness and fainting.
Orthostatic hypotension, also known as postural hypotension, orthostasis, and colloquially as head rush or dizzy spell, is a form of hypotension in which a person's blood pressure suddenly falls when the person stands up or stretches. The decrease is typically greater than 20/10 mm Hg, and may be most pronounced after resting. The incidence increases with age.
Pulse pressure = systolic BP-- diastolic BP. Optimum pulse pressure is 40 mmHg. Pulse pressure > 40 mmHg is a predictor of heart problems.