When you visit your family physician, he is likely to perform several routine measurements to evaluate your overall health: your height, weight, temperature and blood pressure. Blood pressure is a critical measurement of how efficiently your heart is distributing your blood supply throughout your body. For your heart to pump blood to your vital organs and tissues, the left ventricle must exert an appropriate amount of pressure through your circulatory system. If the pressure varies (either too high or too low) you may experience serious health issues.
Basics of Blood Pressure
The body contains approximately 5.5 liters of blood, sometimes more for larger men and less for smaller women. At rest, the heart beats between 60 to 75 beats per minute. Each time the heart beats, the left ventricle squeezes blood through the arteries, where it is delivered to the target organs. After delivering oxygen and nutrients to the tissues, the blood returns to the heart through the veins. In healthy people the pressure of the blood stays within acceptable ranges. However, with diseases such as arteriosclerosis or atherosclerosis, the heart has to work harder to push blood through the arteries to their target organs. This is called hypertension.
Systolic Blood Pressure
To determine if you have normal blood pressure, it's important to measure both pressures, your systolic and diastolic. The systolic blood pressure is the amount of pressure that the blood exerts against the inside of the arterial walls with each beat of the heart. Normal systolic varies between 110 and 120 mmHg (millimeters of Mercury) and is usually written as the first number before a slash (e.g., 120/80). Readings higher than 120 could indicate high blood pressure or hypertension.
Diastolic Blood Pressure
The diastolic blood pressure is the pressure stored in the arterial walls, exerted against the blood in between heart beats when the left ventricle of the heart relaxes and fills. Normal diastolic blood pressure varies between 70 and 80 mmHg and is usually the second number written after the slash (e.g., 120/80). Readings lower than 70 could indicate low blood pressure or hypotension.
Problems with Blood Pressure
Abnormally high or low diastolic blood pressure could be the first symptoms of serious medical conditions. High blood pressure is often the result of arteriosclerosis, or hardening of the arteries. It could also indicate atherosclerosis, a partial or complete occlusion of the coronary arteries that supply blood to the heart.
Low blood pressure can also be caused by excessive blood loss, dehydration from vomiting or diarrhea, low blood volumes (hypovolemia) and certain types of medications. It can also be caused by sudden changes in posture, like suddenly standing from a prone position, called orthostatic hypotension.
Healthy Diastolic Blood Pressure
Monitoring your diastolic blood pressure is an important part of your total health care. Contrary to popular belief, your diastolic is just as important as your systolic. Together the two can provide you with important information about your risk for heart disease and many other diseases. Schedule an annual physical examination with your primary health care provider to have your blood pressure measured by a trained professional. You may also want to buy a blood pressure monitor for home so you can you monitor it yourself in between visits. If you notice unexplained low or high diastolic blood pressures, check with your doctor. You may be able to head off serious illnesses.
