WHAT IS HYPERTENSION? Liz Corrigan Vascular Programme Advisor Office of Public Health Dudley MBC

What is blood pressure? BP is cardiac output/peripheral resistance i.e. how much blood the heart is pumping out over how much resistance the arteries provide to that blood A certain level of BP is necessary for vital organs to function – particularly the kidneys BP is measured in millimetres of mercury (mmHg) Both systolic (top number) and diastolic (bottom number) are important factors in cardiovascular health and risk

How BP is controlled Kidneys in particular are very sensitive to changes in BP If the BP drops the Sympathetic nervous system acts on the heart to increase output and constricts blood vessels to increase resistance In the longer-term, the kidneys release hormones that increase cardiac output and peripheral resistance The adrenal glands also release a hormone which encourages the kidneys to retain salt and increases thirst, this increases blood volume In the very long-term the kidney releases a hormone which promotes red blood cell production and increases blood volume All of this acts to increase blood pressure to ideal levels for that individual

What can influence blood pressure BP can be affected temporarily by a number of things BP rises on waking (there is a fall of 10 – 20% during the night) BP usually rises on standing but patterns flatten out during the day Short-term stressors e.g. anxiety can cause a rise BP will rise if the arm is lowered or if the arm is held rigid during measurement during measurement, and will fall if the arm is raised Incorrect BP cuff size can affect results

Equipment BP is measured using a sphygmomanometer – this can be automatic or manual Automatic machines are simple to use with training and relatively inexpensive (upper arm only!!!) Manual measurement requires more in-depth training All machines should be regularly serviced and calibrated to ensure accuracy Using the correct cuff is important for accurate measurement

Pulse Before checking BP you need to measure the person’s pulse manually If the pulse is irregular the BP reading you get may not be accurate especially with an automatic machine – you may get an error message instead The person will need an ECG If they are unwell re-direct them to A and E

Measuring blood pressure Patient should be seated comfortably with feet flat on the floor The arm should be supported and the cuff level with the heart Either arm can be used unless the person advises you otherwise e.g. breast surgery If the BP is elevated it should be checked again with a gap of no less than 2 minutes If the reading is still elevated it should be repeated again at the end of the consultation

High Blood Pressure BP persistently ≥140/90 (not a one-off reading) Either systolic (top number) or diastolic (bottom number) or both raised This is known as hypertension and requires diagnosis and management by the GP Most people have no symptoms and for most people there is no known cause Hypertension is not a disease, but a risk factor associated with heart disease, kidney disease and stroke

Hypertension assessment required If the BP is ≥ 140/90 mmHg it should be re- checked at the GP surgery in no more than 2 weeks If the BP is ≥ 160/100 mmHg it should be re- checked in no more than 1 week Any diagnoses and decision to treat will be made by the GP

Dangerously high BP If the BP is  180/110 mmHg as this could be accelerated hypertension Accelerated hypertension is a rapid rise in blood pressure to dangerous levels There is a high risk of renal or heart failure, stroke due to damage of the vessel walls, swelling of the brain and brain damage Without effective treatment the survival rate is less than 20% i.e. 4 out of 5 individuals will die Patients with a BP of  180/110 mmHg need to see a doctor on the same day contact the GP by phone/fax

Any Questions