Hypertension

Hypertension, also known as high blood pressure is a long term medical condition in which the blood pressure in the arteries is frequently elevated. High blood pressure usually does not cause symptoms.  Long term high blood pressure is a main risk factor for coronary artery disease, stroke, heart failure, peripheral vascular disease, vision loss, and chronic kidney disease. It is classified into primary high blood pressure or secondary high blood pressure. Due to nonspecific lifestyle and genetic factors about 90–95% of cases are primary hypertension. Lifestyle factors that increase the risk constitute excess salt, excess body weight, smoking, and alcohol. The rest 5–10% cases are due to secondary hypertension, which constitutes chronic kidney disease, narrowing of the kidney arteries, a hormone-related disorder, or the use of birth control pills. Blood pressure is calculated by two measurements, the systolic and diastolic blood pressures, these are the maximum and minimum pressures, respectively. At rest, normal blood pressure is within the range of 100–140 mm of mercury (mmHg) during systole and 60–90 mmHg diastoles.