Blood is carried from the heart to all parts of your body via arteries and in simple terms blood pressure is the force of the blood pushing against the walls of the arteries. It is generated by the heart pumping blood into the arteries and is regulated by the arteries response to the flow of blood. It is measured using a sphygmomanometer and is always expressed in two number the systolic (the top number) and the diastolic (the bottom). The systolic pressure can be defined as the pressure in the arteries when the heart beats and the diastolic pressure can be defined as the pressure in the arteries when the heart is at rest. During diastole the left ventricle of the heart fills with blood returning from the lungs and during systole the left ventricle contracts and pumps blood into the arteries. Generally high blood pressure is a result of the narrowing of the arteries or if more blood is being pumped into the arteries while low blood pressure is a result of less blood is being pumped into the arteries or if the arteries are larger. According to the American Heart Association a pressure equal to or lower than 120/80 is considered normal.
According to the American Heart Association about one in every three U.S adults have high blood pressure. Since there are no symptoms many adults are undiagnosed and the only way to determine if you have have blood pressure is to have your blood pressure checked. Uncontrolled high blood pressure can indirectly cause a stroke, heart failure, heart attack and kidney failure. This is why high blood pressure is often called a silent killer. Apressure between 120/80 - 139/89 is considered prehypertension and a pressure above 140/90 is considered hypertension. Although the primary cause of Hypertension is unknown, it can be caused by another disease (this is more commonly known as secondary hypertension) and usually returns to normal when the cause is treated. Some of the secondary causes include pregnancy, use of birth control pills, thyroid dysfunction, narrowing of the aorta and chronic kidney disease. Certain factors that contribute to the primary cause of hypertension include family history, age, obesity, sodium sensitivity and alcohol use. Treatment for hypertension include the use of several classes anti-hypertensive medications such as ACE-inhibitors, beta-blockers, diuretics, calcium channel blockers, alpha blockers, lifestyle changes in diet and excercise
Hypotension/Low blood pressure
Hypotension is pressure so low that it can cause symptoms due to low blood flow through the body. For many individuals low blood pressure can cause dizziness, fainting, blurred vision, nausea, fatigue and rapid breathing. Severely low blood pressure leads to low blood flow that effects the amount of oxygen and nutrients that are delivered to vital organs such as the kidney, brain, and heart and can cause permanent damage. Low blood pressure can be caused by a reduced blood volume, heart disease and medications. Blood tests, cardiac tests and radiologic studies are tools used to determine the cause and treatment is based on the cause of low blood pressure.