Q&A: THE HIGHS AND LOWS OF BLOOD PRESSURE
Blood pressure is the driving force in your body that keeps blood flowing to every organ. It’s generated by your heart muscle and maintained and transmitted by the blood vessels.
What is blood pressure (BP)?
It’s the force that the blood flowing around your body applies on the inner walls of your arteries – and it’s a measure of how hard your heart is working. Although your average blood pressure should remain constant, there can be fluctuations throughout the day – it could drop when you relax, or rise temporarily if you’re excited or stressed.
What is a normal BP?
It depends on several factors, including age (it rises as you get older) and gender (it’s higher for men). But generally speaking, a normal reading is 120/80.
How is BP measured?
Your healthcare provider puts a blood pressure cuff that incorporates a pressure gauge around your upper arm, and pumps it up, which cuts off the blood flow. They then release the pressure in the cuff, causing the blood to start flowing again, and listen to the sound through a stethoscope. They’ll note the number on the pressure gauge at which blood starts flowing, continue listening until the turbulence has stopped, and then note that number too.
You can take BP at home using a commercially available blood-pressure monitor on sale in pharmacies. Choose a reputable brand and ensure your machine is regularly calibrated or serviced according to manufacturer’s instructions.
What do the two numbers mean?
The first (top) number, called the systolic reading, is the maximum pressure the heart exerts while beating. The second (bottom) number, called the diastolic reading, is the amount of pressure in the arteries between beats. Both numbers are important in monitoring heart health, although most studies show a greater risk of stroke and heart disease related to higher systolic pressures.
What is high BP and what health risks does it carry?
Prolonged high BP (consistently over 140/90) is also known as hypertension. If left untreated, it can cause permanent damage to the cardiovascular system as well as other organs, such as the eyes and kidneys. It also increases your risk of heart attacks and strokes.
What causes high BP?
A range of factors, including your lifestyle and general health. Hypertension runs in families, and it’s more common in people with diabetes, high cholesterol and kidney disease.
How do I know if I have high BP?
Without having it measured, you usually don’t – that’s why it’s often called “the silent killer”. Some people will have symptoms such as headache, dizziness, blurred vision, or nosebleeds, but most have no symptoms.
How is high BP treated?
Lifestyle changes can help – quitting smoking, losing weight, cutting down on alcohol, getting regular exercise, reducing salt intake, and managing your stress. Your doctor may also prescribe medicine:
1. Diuretics (“water pills”) to help your kidneys take salt and water out of your body, which lowers the internal pressure
2. Alpha-blockers to help your blood vessels stay relaxed
3. Beta-blockers to keep your heart from squeezing too hard, and a variety of other meds that work on your brain signals and hormones to stop your blood vessels from tightening up.
Is low BP a problem?
Yes, but it’s not as common as high BP. With low BP, you’ll definitely have symptoms, such as:
1. Dizziness
2. Nausea
3. Blurred vision
4. Difficulty concentrating
5. Shallow breathing
6. Cold sweats
How is low BP treated?
Your healthcare provider will have to determine if there is a medical reason for your low BP. If it’s lifestyle-related, they may advise you to eat more salt, drink more water and wear compression stockings, among other things. You may also be given medicines that cause you to retain sodium and water or tighten your blood vessels, which raises the internal pressure.
Information reviewed and approved by Dr Bianca Vermeulen, a general practitioner and emergency medicine specialist at Mediclinic Midstream.
Images: Supplied, Healthcare Concept, Getty Images
