What do I need to know about blood pressure and COVID-19?

According to Statistics Canada, about one in four Canadians lives with high blood pressure — also called hypertension. 

Yet, doctors say it's one of the most misunderstood and poorly managed conditions out there. A study published in 2017  found that 50 percent of the Canadian public is unaware that they suffer from high blood pressure.

The study found many participants were unwilling to acknowledge the severity of their high blood pressure reading and didn't understand how to manage hypertension properly.

It's a serious problem, says Dr. Nadia Khan, given that heart disease and stroke are the leading causes of death and hospitalization in Canada.

"The thing about hypertension is for the vast majority of people, hypertension is a silent killer. So most people have no symptoms or very mild and nonspecific symptoms," Khan told Dr. Brian Goldman, host of the CBC podcast The Dose. 

Khan, an internal medicine specialist and president of Hypertension Canada, says one of the biggest misconceptions patients have is that they can stop taking their medication without any consequences.

"Fifty percent of people who start on medications for hypertension and even other conditions will not be taking their medication as prescribed by one year," she said, adding that the reasons for that are "complicated." 

It can vary from 'just forgetting' to the cost of the medication, or negative side effects. But sometimes patients believe because they have no symptoms their hypertension is under control, so they stop taking the drugs, thinking they're cured. 

"That's actually a significant misconception. Hypertension is considered a chronic problem. These are long term therapies," she said. 

She said the confusion around blood pressure has increased recently because of COVID-19. 

There were suggestions early in the pandemic that taking common blood pressure medications increased one's chance of getting COVID-19.

But a study published in The New England Journal of Medicine found no links between treatment with four drug classes — ACE inhibitors (angiotensin-converting enzyme , angiotensin receptor blockers (ARBs), beta blockers, or calcium channel blockers—and increased likelihood of a positive test for COVID-19.

"All of the societies that this is relevant to, including Hypertension Canada, the Canadian Cardiovascular Society, the European Society of Cardiology, the European Society of Hypertension, the International Society of Hypertension, are recommending to continue with ACE inhibitor use and continue with angiotensin receptor blocker use, " Khan said. 

In an update this month she said that researchers are now looking into whether the medications may be beneficial in preventing lung damage from COVID-19 and added that the possibility is being studied in multiple trials, including ones in Canada. 

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