Hypertension, or high blood pressure, is a condition in which blood-pressure at rest is higher than the body's needs. Because hypertension lacks overt symptoms, high blood pressure can go unnoticed for years.
metric (Noun). A measurement of the distance between two points in some metric space: it is a real-valued function d(x,y) between points x and y satisfying the following properties: (1) positive definiteness: and, (2) symmetry: , and (3) triangle inequality: . metric (Verb).
The metric unit system is easy to handle because everything is a multiple or a fraction of ten. There is a base unit for each type of measurement, such as meter (abbreviation m) for length, gramm (abbreviation g or gr) for weight or liter (abbreviation l or lt) for volume. Ten base units have the prefix deka (which is however rarely used), for example 1 dekameter (Dm) equals to 10 meters.