High or Low Blood Pressure?

Thursday 18th March 2010 9:21am

blood pressureBlood pressure (BP) is a force exerted by circulating blood on the walls of blood vessels, and is one of the principal vital signs.

Your blood pressure rises and falls during the day but when it stays either elevated or low your health may be at risk.

Low blood pressure

If it is lower than normal then it is called low blood pressure or hypotension.

When arterial pressure and blood flow decrease beyond a certain point, the perfusion of the brain becomes critically decreased (i.e., the blood supply is not sufficient), causing light headedness, dizziness, weakness or fainting.

Excessively low blood pressure may result from a number of different causes. It may be due to reduced cardiac output resulting from a faulty heart valve, abnormal heart rhythms, pulmonary embolism, the weakening of the heart muscle following a heart attack (myocardial infarction), or generalised weakness of the heart muscle due to cardiomyopathy.

It may also result from reduced blood volume (such as might occur through dehydration or massive blood loss); or it might be through excessive dilation of the blood vessels (as could occur in response to septic shock, anaphylaxis (a severe allergic reaction), exposure to heat, conditions of the nervous system or to certain medications). Pregnant women also often have low blood pressure.

High blood pressure

High blood pressure can harm arteries and organs such as the heart, kidneys, brain and eyes.Thankfully though

Persistent hypertension is one of the risk factors for strokes, heart attacks, heart failure and arterial aneurysms, and is the leading cause of chronic renal failure. Even moderate elevation of arterial pressure leads to shortened life expectancy.

A primary risk factor for prehypertension is being overweight. Other risk factors include a family history of hypertension, a sedentary lifestyle, eating high sodium foods, smoking, and excessive alcohol intake.

What the numbers mean

Blood pressure numbers include:

This effectively means that the maximum (systolic) and minimum (diastolic) pressure is measured.

Most often you will see the blood pressure numbers written with the systolic number above or before the diastolic numbers eg 120/80 mmHg.

The mmHg is millimetres of mercury. This relates to the traditional measurement by a sphygmomanometer which historically used the height of a column of mercury to reflect the circulating pressure.

Classification of blood pressure for adults:

It is measured on the inside of an elbow at the brachial artery, which is the upper arm's major blood vessel that carries blood away from the heart.

In the past, most attention was paid to diastolic pressure; but nowadays it is recognised that both high systolic pressure and high pulse pressure (the numerical difference between systolic and diastolic pressures) are also risk factors. In some cases, it appears that a decrease in excessive diastolic pressure can actually increase risk, due probably to the increased difference between systolic and diastolic pressures.

Tips for a healthy heart

  1. Maintain a healthy weight
  2. Be moderately physically active on most days of the week
  3. Follow a healthy eating plan which includes foods low in sodium and dietary sugars
  4. Only consume alcohol in moderation
  5. Do not smoke
  6. Reduce stress
  7. Have your blood pressure checked regularly
  8. Take medication if requiredthat BP

Complimentary medicines that may aid heart health

Did you know?

There are four vital signs which are standard in most medical settings:

This information is not intended as a substitute for qualified medical advice. Please consult a properly qualified health care practitioner.