Hypotension is the medical term for low blood pressure (less than 90/60). A blood pressure reading appears as two numbers. The first and higher of the two is a measure of systolic pressure, or the pressure in the arteries when the heart beats and fills them with blood.Hypotension means Any blood pressure that is below the normal expected for an individual in a given environment. Hypotension is the opposite of hypertension (abnormally high blood pressure).Hypotension is a relative term because the blood pressure normally varies greatly with activity, age, medications, and underlying medical conditions.