blood pumping through the circulatory system is under pressure much like the water in the pipes of a house. and just as too much water pressure can damage pipes and faucets high blood pressure can spell trouble. hypertension occurs when the force exerted against artery walls is abnormally high. over time the increased pressure can cause a wide range of problems. small bulges called aneurysms may form in blood vessels. the heart can become enlarged increasing the danger of heart failure. damage to blood vessels in the kidneys can cause them to fail. because tiny blood vessels in the eyes are especially vulnerable to damage hypertension can lead to vision problems and even blindness. many factors can lead to high blood pressure. clearly diet plays a role. too much salt too little potassium and heavy drinking have all been found to increase the risk of high blood pressure. too much stress and too little physical activity both increase the danger of developing high blood pressure as does being overweight or obese. and as with many chronic illnesses high blood pressure also tends to run in families suggesting that genes play a role. in some patients high blood pressure is related to other medical problems or to the use of certain medicines. this form of the disease is called secondary hypertension because it is secondary to other medical conditions. high blood pressure is usually diagnosed using the familiar blood pressure test that involves a cuff wrapped around the upper arm. the cuff is inflated and then sensors measure the pressure of blood beating against the arteries. blood pressure is measured using two numbers? systolic and diastolic pressure. systolic the upper number is the pressure when the heart is beating. diastolic the lower number is the pressure between beats. normal blood pressure is considered to be anything below 120/80. prehypertension is defined as a systolic reading between 120 and 139 and a diastolic reading between 80 and 89. hypertension is defined as blood pressure of 140/90 or higher. for people with diabetes or chronic kidney disease hypertension is defined as 130/80.
what is high blood pressure?