英文解说词：High Blood Pressure
Blood pressure (BP) is the pressure exerted by the blood flow on the walls of the arteries. It is the determined by the force and amount of blood pumped by the heart and by the diameter of the arteries. It consists of two components Systolic pressure and Diastolic pressure. These are normally 120 and 80 mmHg respectively. When the blood pressure exceeds these values , it leads to a condition called High blood pressure or hypertension.
There are two types of Hypertension, primary and secondary hypertension. Primary hypertension is hypertension without a specific identifiable cause. Secondary hypertension is elevated blood pressure that results from an underlying, identifiable, often correctable cause. Only about 5 to 10 percent of hypertension cases are thought to result from secondary causes.. The most common causes of secondary hypertension are kidney disease, adrenal gland disease, narrowing of the aorta and sleep apnea.
Hypertension frequently causes few or no symptoms, therefore regular blood pressure checks should be done to diagnose hypertension. When symptoms occur, the most common symptoms are headaches, dizziness, and blurred vision. In severe cases, confusion and coma are possible.
Blood pressure is usually measured with a small portable instrument called a blood pressure cuff or the sphygmomanometer. The blood pressure cuff consists of an air pump, a pressure gauge, and a rubber cuff. The instrument measures the blood pressure in units called millimeters of mercury (mmHg).
A blood pressure reading of 120/80mmHg is considered normal whereas a blood pressure of 140/90mmHg or higher is considered high blood pressure or hypertension.
Hypertension can be managed by changes in lifestyle such as by quitting smoking, eating a diet lower in cholesterol and salt, getting regular exercise, and by taking antihypertensive drugs such as beta blockers or other anti-hypertensive