<P> High blood pressure is classified as either primary (essential) high blood pressure or secondary high blood pressure . About 90--95% of cases are primary, defined as high blood pressure due to nonspecific lifestyle and genetic factors . Lifestyle factors that increase the risk include excess salt in the diet, excess body weight, smoking, and alcohol use . The remaining 5--10% of cases are categorized as secondary high blood pressure, defined as high blood pressure due to an identifiable cause, such as chronic kidney disease, narrowing of the kidney arteries, an endocrine disorder, or the use of birth control pills . </P> <P> Blood pressure is expressed by two measurements, the systolic and diastolic pressures, which are the maximum and minimum pressures, respectively . For most adults, normal blood pressure at rest is within the range of 100--130 millimeters mercury (mmHg) systolic and 60--80 mmHg diastolic . For most adults, high blood pressure is present if the resting blood pressure is persistently at or above 130 / 90 or 140 / 90 mmHg . Different numbers apply to children . Ambulatory blood pressure monitoring over a 24 - hour period appears more accurate than office - based blood pressure measurement . </P> <P> Lifestyle changes and medications can lower blood pressure and decrease the risk of health complications . Lifestyle changes include weight loss, decreased salt intake, physical exercise, and a healthy diet . If lifestyle changes are not sufficient then blood pressure medications are used . Up to three medications can control blood pressure in 90% of people . The treatment of moderately high arterial blood pressure (defined as> 160 / 100 mmHg) with medications is associated with an improved life expectancy . The effect of treatment of blood pressure between 130 / 80 mmHg and 160 / 100 mmHg is less clear, with some reviews finding benefit and others finding unclear benefit . High blood pressure affects between 16 and 37% of the population globally . In 2010 hypertension was believed to have been a factor in 18% of all deaths (9.4 million globally). </P> <P> Hypertension is rarely accompanied by symptoms, and its identification is usually through screening, or when seeking healthcare for an unrelated problem . Some with high blood pressure report headaches (particularly at the back of the head and in the morning), as well as lightheadedness, vertigo, tinnitus (buzzing or hissing in the ears), altered vision or fainting episodes . These symptoms, however, might be related to associated anxiety rather than the high blood pressure itself . </P>

Which of the following is an example of hypertension