What is low blood pressure?
BP in simple terms is the force that the heart exacts as it pushes blood round the vessels of the body. BP is generated by the strength of the heart’s pumping action and is partly caused by the resistance of the blood vessels to the flow of blood around the body.
A persons blood pressure level is expressed by two numbers. The upper number is called systolic level. The lower number is called the diastolic pressure.
These two numbers are usually written with a slash in between. For example you might see the numbers written like 120/80. Another common reading made to be 100/61.
The systolic number represents the maximum heart reaches when it is contracting. The diastolic one represents the relaxation state of the heart just before it begins the next phase of pumping.
For most healthy adults the upper number falls somewhere between 90 and 120. The lower number — the diastolic blood pressure number — falls between 60 and 80.
According to current guidelines the normal BP level is around 120/80. Any BP higher than 130 or higher than 80 is said to be slightly high. A BP reading higher than 160 or higher than 90 is definitely high.
If you have high BP levels then you are at increased risk of developing heart disease, kidney disease, hardening of the arteries, stroke or heart attack.
Low blood pressure is a different kettle of fish. It tends not to cause any lasting damage to the blood vessels but it does sometimes cause symptoms or signs because the flow of blood through the arteries is not sufficient.
The body depends on blood to get oxygen into the vital organs like the brain, heart and kidneys. If the blood pressure is too low in these organs might not gain enough blood.
Unlike hypertension we normally define low BP in terms of the symptoms of low blood flow and not usually like any one specific number. An example of this is that someone can have numbers of 90/50 and feel entirely well while another person will have the same numbers but be unable to rise from a chair or their bed.
If you are struggling to deal with the symptoms of low blood pressure then check out some facts and figures here. Doctor Gordon Cameron outlines the issues that are often associated with low blood pressure and the way it is treated.
