Taking the blood pressure is one of the most common and useful ways of measuring variations in someone’s health. It forms a standard part of an orthodox medical examination and is widely accepted as a barometer of stress. By measuring blood pressure, it is possible to tell how hard the heart has to work to pump blood round the body.
The measurement is taken by placing an inflatable cuff around the upper arm. This is then pumped up until it exerts enough pressure to stop the flow of blood in the arm’s main artery. As the cuff is gradually deflated and the blood begins to flow again, readings are taken on a gauge at two points of the heart’s pumping cycle. The first reading, of the systolic pressure, is taken at the moment when the heart actually beats (peak pressure); the second, called the diastolic pressure, is measured between heart beats (lowest pressure). The two readings are combined as a fraction with systolic pressure over diastolic pressure.
A normal measurement for an adult is about 120 over 80 (though blood pressure varies slightly throughout the day depending on what you are doing). However, systolic pressures of 100-140 and diastolic measurements of 60-90 are usually considered within normal bounds. Indeed, most doctors now regard a systolic reading of 100 plus a patient’s age as acceptable and would not necessarily be concerned by 60 year old with a systolic blood pressure of 160.
Abnormally high blood pressure is known as hypertension; low blood pressure is called hypotension. Both conditions may require treatment although hypertension is usually regarded as the more serious. High blood pressure is most common among the middle-aged (about one in 10 is affected), particularly men. It is an invisible disease and many people are completed unaware that they have it, although others experience symptoms such as headaches, dizziness, or ringing in the ears.
Most cases of hypertension result from a combination of factors. Any one or more of the following can cause high blood pressure: being overweight, drinking too much, eating too much salt, insufficient exercise, hardening of the arteries, taking the contraceptive pill, smoking or hereditary factors. In rare cases, the cause may be a kidney disorder, and some pregnant women develop dangerously high blood pressure. If high blood pressure continues unchecked, it can contribute to serious conditions such as angina, heart attack, stroke, haemorrhage, or kidney complaints.
Low blood pressure can be as hard to detect as the opposite extreme. It mostly affects elderly people and is usually temporary. The symptoms, if there are any, include momentary giddiness or fainting on standing up suddenly after sitting or lying down.
When low blood pressure is persistent, it may be due to an under active adrenal gland.