High Blood Pressure: Natural Self-help for Hypertension, including 60 recipes. Michelle Berriedale-Johnson
rests (diastole) is known as the diastolic pressure. In general, as the heart pumps more strongly, systolic pressure rises, while a reduction in elasticity of the peripheral arteries causes diastolic pressure to go up.
How BP is Measured
Blood pressure (BP) is measured using an instrument called a sphygmomanometer. This has an inflatable cuff which goes around your upper arm, a small pump to push air into the cuff and a column of mercury (or a dial) to record the pressure within the cuff.
As the cuff is inflated with air, the person measuring your BP usually feels for a pulse (brachial artery) in the crook of your elbow. While the pressure within your artery stays higher than that in the cuff, blood can be felt pulsing through. Once the pressure in the cuff becomes greater than that in your artery, the vessel is squashed flat and blood stops flowing through it at that point. By inflating the cuff to an initial pressure that is higher than the expected systolic pressure, then listening with a stethoscope over your brachial artery as the pressure is slowly released, the point at which blood manages to squirt through again with each pulse can be heard distinctly as a tapping sound. The pressure registering in the cuff at this point is taken as your systolic BP. The cuff is then slowly deflated further while listening over your artery. The tapping sounds become louder, then change to a dull whooshing noise before disappearing. The point at which blood can no longer be heard whooshing through the vessel is taken as your diastolic BP. The pulsing noise heard in the artery between these two pressures is a result of turbulence as the cuff impinges on the vessel and deforms its walls. We therefore know that the blood pressure in the artery is the same as that in the cuff at the point where the sounds disappear, as turbulence is no longer occurring. BP can also be measured with modern digital cuffs that fit around the wrist.
BP is measured according to the length of a column of mercury it can support. It is therefore expressed in millimetres of mercury (mmHg). BP is written down as the higher pressure (systole) over the lower figure (diastole).
How Blood Pressure is Controlled
Blood pressure is normally controlled and kept within safe limits by the body in a number of ways, including:
These factors are controlled by nerve signals from the brain, and by several different hormones. As a result, normal BP varies naturally throughout the day, going up and down in response to your emotions and level of activity. It is lowest during sleep (usually at around 3am) and highest in the morning from just before you wake until around 11 am. If you have high blood pressure, however, your BP will remain high all the time, even at rest.
Hypertension
As many as one in five adults have high blood pressure, known medically as hypertension. This means that blood is forced through their system under a constantly high pressure. Hypertension is diagnosed when systolic pressure is consistently greater than 140 mmHg and diastolic pressure consistently greater than 90 mmHg. A systolic blood pressure between 140–160 mmHg and diastolic values between 90–95 mmHg are sometimes referred to as mild hypertension.
In hypertension, the body’s systems for correcting high or low blood pressure don’t seem to work properly so blood pressure is maintained at an elevated level compared to normal. Little is known about how or why this happens, but the condition seems to be readily reversible once diet and lifestyle changes are introduced, together with any necessary anti-hypertensive drug treatment.
SYMPTOMS
Unfortunately, people with high blood pressure usually notice very little in the way of symptoms, although a few may develop a pounding sensation in their ears or a splitting headache. As a result, hypertension is often referred to as the silent killer, as it usually creeps up on you without any obvious warning. Even if your blood pressure is dangerously high, you may feel relatively well. If symptoms do occur, they tend to be non-specific, such as a headache or getting up at night to pass urine more often than normal. Your blood pressure has to be severely raised before you develop dizziness or visual disturbances. It is therefore a good idea for adults to have their blood pressure checked on a regular basis, every year or so – especially if high blood pressure runs in their family. This is because a high blood pressure that remains undiagnosed and untreated can lead to a number of potentially serious complications.
WHY HIGH BLOOD PRESSURE IS HARMFUL
Hypertension is not a disease in itself, but a clinical sign that you are at increased risk of a number of serious health problems. As blood is forced through your system at high pressure, your artery walls receive a pounding. This which can both over-stretch important blood vessels as well as damage their linings. If left untreated, this can trigger premature hardening and furring up of the arteries (atherosclerosis) and increase the risk of a number of health problems. If your blood pressure remains constantly high, this can lead to: