hyper-

hyper-, hypo-

These prefixes are derived from Greek prepositions huper and hupo meaning ‘over, above’ and ‘under, below’ respectively. In English, hyperthermia means ‘abnormally high body temperature’ and hypothermia means ‘abnormally low body temperature’; hypertension means ‘abnormally high blood pressure’ and hypotension means ‘abnormally low blood pressure’. Both prefixes are usually pronounced in the same way (hiy-pǝ), and the meaning may have to be clarified by the context in which they are used. In other words the prefix does not correspond so closely to sense; for example, hypochondria means ‘excessive anxiety about one's health’ (suggesting hyper- rather than hypo-) and is derived from a Greek word meaning ‘the soft parts of the body below the ribs’, where such feelings were thought to arise. Hypercritical duly means ‘excessively critical’, but hypocritical and hypocrisy (pronounced hip-, not hiyp-) are derived from a Greek word hupokrisis meaning ‘acting a part, pretence’.