High blood Pressure AKA Hypertension
High blood Pressure AKA Hypertension
By Dr I Abrahams (MBChB, UCT)
What is blood pressure
Blood pressure is the force that blood exerts on the walls of our arteries either when the heart is beating or in between beats when the heart rests. The pressure when the heart is beating (or systolic pressure) is the maximum pressure that the heart will exert on your arteries during a single “beat-rest” or cardiac cycle. During the heart’s “rest” period it fills up with blood in preparation to pump again. The pressure in your arteries when the heart isn’t pumping (diastole) is the diastolic blood pressure.
Blood pressure is measured as a figure over another figure like a fraction. Where the top number is the systolic pressure and the bottom number is diastolic pressure.
Blood pressure systolic/ diastolic e.g. 120/80 where systolic pressure is 120 and diastolic pressure is 80. The unit of measure is called mmHg or “millimeters of mercury”.
Fun fact: mmHg is an old unit of measurement we used to use with old pressure meters that caused the element, mercury, to rise in a column when pressure was applied to the machine. The millimetres the column raised was then recorded as the force.
What is high blood pressure
High blood pressure simply is a systolic blood pressure greater than 140mmHg or diastolic pressure of 90mmHg or higher.
Note: Different countries have different cuff-offs for what is considered high.
What causes High blood pressure
Essential or Primary hypertension
This is the most common type of high blood pressure. This is associated with lifestyle issues e.g. lack of exercise, high salt intake, age, obesity and genetics. There is, however, no clearly identifiable single risk factor for the development of Primary Hypertension.
Secondary Hypertension
This is a less common type of high blood pressure caused by another clearly identifiable medical condition. Some examples of causes include:
Pregnancy related→ Pregnancy induced hypertension, Pre-eclampsia.
Hyperthyroidism: overactive thyroid
Drugs especially stimulants like Methamphetamines, Cocaine, Ritalin ®, Caffeine, oral decongestants
Renal artery stenosis
Co-arctation of the aorta
Some tumours or cancers
Chronic oral steroid use → e.g. Prednisone, testosterone, Prednisilone
When to be concerned about secondary hypertension
Young hypertensive Age <30.
Resistant Hypertension. BP still high despite treatment
Hypertension in pregnancy
Drug use
High blood pressure before puberty
Why does it make a difference if it’s primary or secondary?
Secondary causes need to be treated to either cure your high blood pressure or even keep it under control at all.
How bad is my blood pressure?
Severity | Systolic (mmHg) | Diastolic (mmHg) |
Normal | <120 | <80 |
High normal | 120-130 | 80-85 |
Prehypertension | 130-139 | 85-89 |
Hypertension (mild) | 140-159 | 90-99 |
Hypertension (moderate) | 160-179 | 100-109 |
Hypertension (severe) | ≥180 | ≥110 |
Please note: If your blood pressure is in the severe range seek medical care as soon as possible as your blood pressure needs to be lowered under professional guidance. Professional review is urgent and thus this condition is called a Hypertensive Urgency.
If, however, you have any of the following symptoms suddenly devlope alongside severe high blood pressure, seek immediate emergency services without any delay:
Chest pain especially if it’s worse on exertion
Shortness of breathe
Sudden exhaustion after only minor exertion
Severe Headache
Dizziness
Weakness on one side of the body, slurred speech, confusion or drooping face
Vision problems
When in doubt regardless of blood pressure. The rule is that if you’re unsure of what to do, consult emergency services. Wasting time can result in irreversible damage.
The above is called a Hypertensive Emergency and needs urgent care. Do not concern yourself with the specific number. If your blood pressure is high and you have the following symptoms rather be assessed by emergency services as a matter of urgency. Some people can experience sudden organ damage at pressures lower than 180/110.
How do I take my blood pressure
Use a blood pressure cuff that is meant to be around your upper arm. Wrist cuffs are not as accurate.
Make sure your blood pressure cuff fits. The cuff should sit comfortably on your arm and not pop off when inflated. The cuff should also not slide off from your arm when applied prior to inflating.
Rest for 15 minutes before taking blood pressure. Sit and rest without talking.
Apply the cuff to a bare arm (no coverings on the upper arm) about 2cm above the crease in your arm and ensure the bladder (balloon) of the cuff is over the bicep area. Sit up straight with your arm at heart level.
Ensure you follow the directions of any arrows and instructions on your specific machine.
Make sure the artery line on your cuff is over the brachial artery (shown below)
Take the reading at the same time each day to get a good trend.
You can use either arm to take your blood pressure. Repeated readings on the same arm in quick succession can cause pain and give false readings. If you need to repeat your blood pressure, use the other arm.
With your hand facing up the artery is in the direction of your little finger side of the arm.
Dangers of high blood pressure
Stroke
Sudden death
Chronic kidney disease
Ischaemic heart disease including heart attacks
Aneurysms- dangerous dilation of arteries
Vision loss
Heart or kidney failure
Decreased quality of life overall
Should i take my meds before i go to my doctor’s appointment
Unless told specifically not to, Always take your medication. It makes a doctors job much harder to see if your medication is controlling your blood pressure if you did not take your tablets that day. He/she might give you more medication assuming your BP isn’t under control.
What can I do to naturally decrease my blood pressure or prevent high blood pressure
Decrease caffeine intake
Avoid drugs and smoking
Limit alcohol intake
Avoid adding salt to food
See a dietician to help modify your diet
Exercise
Control other chronic illnesses
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