Sample: Serum, Plasma
Remarks: Hypertension (high blood pressure) is a serious medical problem because: it is quite common, it may be fatal and it remains asymptomatic until late in the course. It is the single most important risk factor in coronary disease and cerebovascular episodes and it may lead both to heart and renal failure. Hypertension may be defined as a sustained diastolic pressure above 90 mm Hg. A sustained systolic pressure above 140 mm Hg may also constitute hypertension.