O what is the difference between systolic and diastolic pressure

When a person receives their blood pressure results, they will see two numbers that represent the diastole and systole measurements. These measurements are given as millimeters of mercury mm Hg. These updated guidelines are likely to place 46 percent of Americans in the category of having high blood pressure. Blood pressure is always measured when the person is at rest and over several days. Its measurements are also called blood pressure readings. Both high and low blood pressure can cause serious health consequences if left untreated.

High blood pressure or hypertension is when a person has abnormally high pressure against the walls of their blood vessels. This condition develops gradually over many years and may go unnoticed for a long time, as there are often no symptoms. When left untreated, high blood pressure can cause complications and, eventually, serious health problems, such as:.

Low blood pressure or hypotension occurs when a person has abnormally low blood pressure against the walls of their blood vessels. A person with mild low blood pressure may experience fatigue , fainting, or dizziness. If this happens, a person may feel sleepy, confused, or light-headed. In serious cases, this can evolve to heart or brain damage. Diastole and systole are two phases of the cardiac cycle.

They occur as the heart beats, pumping blood through a system of blood vessels that carry blood to every part of the body. Their evaluation of blood pressure measurements and mortality risk found that diastolic and pulse pressure measurements were weaker indicators of mortality risk and their effect was more dependent on age and other factors.

The study appears in the November 4, , edition of the Annals of Internal Medicine. Systolic pressure, which is the higher number and first number in a blood pressure reading, measures the force of blood in the arteries as the heart contracts to push blood through the body. Doctors consider a systolic blood pressure greater than mm Hg millimeters of mercury as unhealthy and can lead to heart disease, stroke, and vascular diseases of the legs.

Diastolic pressure, the lower number, measures the pressure as the heart relaxes to fill with blood. There are no treatment studies of isolated diastolic hypertension. Pulse pressure reflects stiffening of large arteries and is associated with several cardiovascular risk factors. Pulse pressure also predicts events in epidemiologic studies, but elucidation of an independent role is hampered by the close correlation between pulse pressure and systolic blood pressure.

Summary: Epidemiological and treatment studies suggest that systolic blood pressure should be the primary target of antihypertensive therapy, although consideration of systolic and diastolic pressure together improves risk prediction. Diastole — this period of time when your heart relaxes between beats — is also the time that your coronary artery is able to supply blood to your heart.

Your blood pressure may be normal, high, or low. High blood pressure is also referred to as hypertension, and low blood pressure is called hypotension. The American Heart Association describes the different blood pressure ranges for adults as:. Your doctor may diagnose high blood pressure if either your systolic or diastolic is high, or if both numbers are high. Both high blood pressure and low blood pressure need to be managed. According to the American College of Cardiology , almost half of the adults in the United States now fit the new definition of high blood pressure.

Not surprisingly, the risk factors for these two conditions are very different. Your gender affects your risk of high blood pressure. The American Heart Association states that men are at a higher risk of high blood pressure than women are until age But at 65 years and older, women are at higher risk than men. Your risk is also higher if:. When your breathing is inadequate, your oxygen levels fall and your blood vessels constrict.

This increases your blood pressure. When sleep apnea is persistent, this increased blood pressure may continue during the day when breathing is normal. Properly treating sleep apnea will help lower blood pressure.

Endocrine problems, neurological diseases, heart problems, heart failure , and anemia may also cause the condition. You may also be at risk for low blood pressure if you become dehydrated or take certain prescription drugs such as:.

Low blood pressure can also be caused by a variety of heart, hormonal, or nervous system problems. These include:. Lifestyle changes are recommended as the first step in treating any stage of high blood pressure.