What is high blood pressure?

What is high blood pressure? Also called hypertension, it is one of the most common medical conditions worldwide. Yet, because it rarely has noticeable symptoms, around half of those with the condition don't know they have it. This is a problem because, if untreated, high blood pressure can lead to serious medical problems. 

But what is blood pressure anyway?

The heart pumps blood around the body, delivering oxygen and nutrients through a system of pipes called blood vessels. As the blood flows through our bodies, it creates a force against the wall of the blood vessels called the blood pressure. This force rises and falls with every heartbeat. It is highest during systole, when the heart beats, and is lowest during diastole, when the heart relaxes in between beats. 

A blood pressure reading therefore includes two numbers. A normal systolic blood pressure is between 90 and 120, and a normal diastolic blood pressure is between 60 and 80. A reading regularly above 140 over 90 is called high blood pressure or hypertension. Our blood pressure goes up and down throughout the day, depending on how hard the heart is pumping, the overall blood volume and the resistance in the blood vessels. For example, in active or stressful situations, the heart beats faster and the blood vessels narrow, temporarily raising blood pressure. So how does the condition hypertension develop? Healthy blood vessels do have a bit of give or elasticity like a rubber band that allows them to cope with changes to blood pressure. However, different risk factors reduce this elasticity and increase resistance in the blood vessels leading to persistently high blood pressure. 

These risk factors include increasing age, a poor diet, smoking, drinking too much alcohol, being overweight, physical inactivity, ethnic background and family history, High blood pressure can also be related to, or directly caused by, other health conditions or certain medications. 

Why is high blood pressure bad for our health?

It is often called a silent killer because it doesn't usually cause symptoms on its own. However, over time, high blood pressure strains the blood vessels and leads to tiny tears within the blood vessel walls. These tears increase the risk of fatty buildup or clots, which can narrow or block the blood vessel. If this happens in the brain it can lead to a stroke, in the heart it can lead to a heart attack and in the kidneys it can lead to kidney disease. 

Also, as the heart has to work harder to pump blood around the body, it can also lead to heart failure. Blood pressure is measured using a blood pressure cuff as it is inflated around the upper arm and readings can be taken either manually or electronically. As blood pressure fluctuates from moment to moment, several readings are needed over time to get a reliable measure. Electronic kits can be easily used at home for regular monitoring. If high blood pressure is diagnosed, a doctor may arrange further tests to check for risk factors and signs of damage. 

How can blood pressure be treated and controlled?

There are many lifestyle changes that can help maintain a healthy blood pressure. These include eating healthy foods with less processed salty food and more fruit and vegetables, being more active, maintaining a healthy weight, not smoking and reducing alcohol intake. Doctors may also recommend one or more medications to control blood pressure. Some work on the heart, reducing the speed and strength of the heartbeat. Others work on the kidney to lose more water, reducing blood volume. And many work directly or indirectly on the blood vessels themselves, causing them to relax and widen. Each type of medication may lead to different side effects in some people. If these are troublesome, speak to your doctor, who can suggest an alternative medication or change the dose. It's important to take medication as prescribed and to monitor blood pressure regularly to check it's under control. High blood pressure is an important condition but it can be controlled and it is also largely preventable. Adopting healthy habits now will help to prevent serious consequences later in life.