High blood pressure affects about 50 million Americans and 1 billion people worldwide.
Blood pressure measures the force of blood pushing against the walls of the arteries as the heart pumps blood. It is highest near your heart and in the major arteries and lowest in small arteries and capillaries. Because it varies, blood pressure is taken in a standardized place, usually on the inside of your upper arm along the brachial artery.
The upper number, systolic blood pressure, measures the pressure in the arteries when the heart pumps blood throughout the body. The lower number, diastolic blood pressure, is the pressure in the arteries when the heart is relaxing. Healthy blood pressure should be around 120/80 or lower. When the systolic pressure is greater than 120 and the diastolic pressure is greater than 80, patients are diagnosed as having high blood pressure. These levels have recently been lowered from 140/90. Different levels are used for children and adolescents.
High blood pressure is called hypertension and can lead to a number of serious conditions, including coronary heart disease, heart failure, stroke, and kidney failure. Elevated blood pressure levels can make you tired, give you headaches, cause vision problems, and give you an upset stomach, or there can be no symptoms.
Low blood pressure is called hypotension and can result in a decrease in the amount of blood being pumped to the brain resulting in lightheadedness, dizziness, weakness, and fainting. Extremely low blood pressure can also be a sign of a severe cardiac disease and should be taken just as seriously as high blood pressure.