What is it?
Pressure is exerted by the heart contracting against the resistance of the smaller blood vessels. The peak pressure as the heart contracts is called the systolic blood pressure and the lower pressure when the heart relaxes is called the diastolic blood pressure. Thus, two measures are recorded. A typical pressure in a young man might be 120/80mmHg.

Blood pressure readings always have two numbers, one number on top of the other, for example 140/90.
The top number is your systolic blood pressure. (The highest pressure when your heart beats and pushes the blood round your body). The bottom number is your diastolic blood pressure(The lowest pressure when your heart relaxes between beats).

Both the systolic and diastolic pressure measurements are important - if either one is raised, it means you have high blood pressure (hypertension).

Blood pressure is important because high blood pressure is a risk factor for strokes and heart attacks. A 10mm rise in diastolic blood pressure is associated with approximately doubling the risk of stroke and a 50% increase in the risk of a heart attack. This is not as alarming as it may seem at first sight. If the risk of a heart attack or stroke is very low, as it is in young people without other risk factors such as high cholesterol or regular smoking, borderline blood pressure elevation dose not pose a significant threat. As individuals become older, however, or when these other risk factors are present, slightly elevated blood pressure presents a much greater risk. Blood pressure is not, therefore, treated in isolation.

There is no single value of blood pressure for healthy individuals since blood pressure changes with age and differs in the two sexes. Blood pressure normally gradually rises with age, so that the level at which your blood pressure will be considered high will change as you get older. The average blood pressure considered to be normal is 120/80 yet can reach 140/90 before being classed as special attention. There is however, a wide spread of values on each side of these but higher blood pressures may need treatment.

Categories for Blood Pressure Levels in Adults (in mmHg, or millimeters of mercury)

Category Systolic (top number) Diastolic (bottom number)
Normal Less than 120 And Less than 80
Prehypertension 120–139 Or 80–89
High blood pressure(hypertension)
Stage 1 140–159 Or 90–99
Stage 2 160 or higher Or 100 or higher

The ranges in the table apply to most adults (aged 18 and older) who don’t have short-term serious illnesses.

All levels above 120/80 mmHg raise your risk, and the risk grows as blood pressure levels rise. “Prehypertension” means you’re likely to end up with HBP, unless you take steps to prevent it.

If you’re being treated for HBP and have repeat readings in the normal range, your blood pressure is under control. However, you still have the condition. You should see your doctor and stay on treatment to keep you blood pressure under control.

Your systolic and diastolic numbers may not be in the same blood pressure category. In this case, the more severe category is the one you’re in. For example, if your systolic number is 160 and your diastolic number is 80, you have stage 2 HBP. If your systolic number is 120 and your diastolic number is 95, you have stage 1 HBP.

Preventing high blood pressure
Blood pressure is a characteristic of the individual, although one which can vary quite markedly on different occasions. Like height and weight it is the product of a mixture of factors. Inheritance is important and some patients with high blood pressure have a parent or sibling who has also suffered from elevated blood pressure, although this may not always be known by the individual.

More specifically, reducing stress, taking exercise and moderating your diet, particularly salt and alcohol, all contribute to lowering blood pressure.

There is an extremely wide choice of drugs which lower blood pressure, and effective control of blood pressure without unacceptable side effects is now possible in almost every patient. Except in patients at high risk, the accepted practice is to recommend ‘lifestyle’ changes and observe blood pressure over a period of several months.

Hypotension
Hypotension is usually associated with blood pressure that’s lower than 90/60 mmHg.

Your body is very sensitive to changes in blood pressure. Special cells in the arteries can sense if your blood pressure begins to rise or fall. When this happens, the cells trigger your body to try to bring blood pressure back to normal.

For example, if you stand up quickly, your blood pressure may drop. The cells will sense the drop and will quickly take action to make sure that blood continues to flow to your brain, kidneys, and other important organs.

Most forms of hypotension happen because your body can’t bring blood pressure back to normal or can’t do it fast enough.

Some people have low blood pressure all of the time. They have no signs or symptoms, and their low blood pressure is normal for them. In other people, certain conditions or factors cause blood pressure to drop below normal.

Hypotension is a medical concern only if it causes signs or symptoms, such as dizziness, fainting, or, in extreme cases, shock.

If you liked this article, why not subscribe to Body Charge RSS Feed.
Alternatively subscribe here to receive new articles by email.