What Causes a Change in Blood Pressure and Why?

Blood pressure can be a very important indicator of the state of your overall health. This is undoubtedly why most visits to your family doctor include taking a reading of your blood pressure levels. Blood pressure readings are composed of two numbers, rendered, for example, as 120/80. The first or top number is your systolic reading (a measure of maximum arterial pressure when the heart contracts), and the second or bottom number is the diastolic reading (minimal arterial pressure when the heart rests).

What Is Normal?

• Medical professionals differ to some small degree about the range of normal blood pressure readings, but most seem to agree that a reading in the neighborhood of 120/80 is close to optimal. Anything above 140/90 is likely to get your doctor's attention and prompt him to order further testing. Anything significantly lower than 120/80 may also be cause for alarm. Be aware that a single blood pressure reading outside the normal range should not in itself be a cause for concern, but three or more readings outside the normal range over a span of several days or even weeks is a clear sign that something's amiss.

Hypertension

• Blood pressure readings consistently higher than normal indicate that you are suffering from hypertension, or high blood pressure. This condition can be caused by several factors, some of which could account for an isolated spike but not abnormal readings over the long haul. Sadly, according to the American Heart Association (AHA), the cause cannot be identified in 90 to 95 percent of all cases of high blood pressure, which is one reason hypertension is often referred to as the "silent killer." The culprits in 5 to 10 percent of all cases could be kidney malfunction, a structural defect of the aorta or the narrowing of certain arteries, according to the AHA. Causes of isolated spikes in blood pressure include high sodium intake or nervousness, a reaction sometimes associated with a visit to the doctor.

Low Blood Pressure

• If you are troubled by dizziness, lightheadedness or even fainting spells, it is possible that you are suffering from low blood pressure, also known as hypotension. This, too, can occur on an isolated basis, reflecting a response to medication or getting up too quickly from a seated position. Causes of consistently low blood pressure, according to the AHA, include a drop in blood volume because of excessive blood loss or dehydration, prolonged bed rest, and endocrine or nerve disorders.

What to Do

• Although doctors may be unable to pinpoint the cause of hypertension in most cases, they have at their disposal a wide array of medications that can keep high blood pressure under control. In the case of hypotension, the causes are generally more clear-cut and often can be addressed without resorting to medication. Whatever the case, abnormal blood pressure readings are a sign of some underlying problem and must not be ignored.

Potential Risks

• As mentioned above, hypertension is often referred to as a "silent killer." If that is not enough to encourage you to seek help, maybe you'll be stirred to action to read about some of the diseases associated with untreated high blood pressure. These include heart disease, stroke and kidney disease. Hypertension is found frequently in patients who have been diagnosed with diabetes and may be explained as "part of the metabolic syndrome of insulin resistance," according to the American Diabetes Association.