How Does Blood Pressure Work?

iStock
iStock

Your heart is the master pump for all the blood in your body. With every heartbeat, your heart pushes your blood to all the vital parts of your body, such as muscles and bones, through a network of arteries, capillaries, and veins. As blood flows through the tube-like arteries, it presses up against the walls of the blood vessels with varying degrees of strength. The strength or weakness of this pressure is called your blood pressure (BP).

Each time your heart squeezes, moving your blood to its various destinations, your blood pressure goes up—this number is referred to by a blood pressure reading as systolic. Then, as the heart relaxes after each contraction, your blood pressure goes down; that is called the diastolic reading. Together, these two numbers are presented as a score, systolic over diastolic: Your doctor might tell you that your BP is “120 over 80.”

According to the American Heart Association (AHA), normal blood pressure should reflect systolic pressure between 90 and 120, over a diastolic pressure between 60 and 80. Your doctor may take this measurement with a fancy-named instrument called a sphygmomanometer—an inflatable rubber cuff attached to a manual air pump. When the doctor inflates the cuff at your arm with air, it temporarily cuts off blood flow, and when it releases, the blood starts flowing again, revealing those two key numbers.

Nowadays, though, doctors are recommended to use an automatic blood pressure cuff, which relies on a different method and seems to be more accurate. While the manual cuff relies on auscultation, in which the doctor listens for the correct pressures using a stethoscope/microphone, automatic blood pressure cuffs are usually oscillometric. When blood passes under the cuff, the arm increases in circumference ever so slightly. And by measuring the amplitude of the oscillations (hence oscillometric) at a continuous interval of pressures, blood pressure can be calculated in much the same way.

If you have high blood pressure, a.k.a. hypertension—approximately 130/80 or higher in a person of average health—your heart is working too hard to pump the blood through your body, which becomes dangerous. According to the AHA [PDF], elevated blood pressure is 120–129/less than 80; hypertension stage 1 is 130–139 (systolic) or 80–89 (diastolic); and hypertension stage 2 is 140 or higher (systolic) or 90 or higher (diastolic). If your blood pressure hits 180/120, you're in hypertensive crisis, and you should get help.

If you fall into the above categories, your doctor will recommend changes to diet and exercise and probably medication. High blood pressure is often a precursor to heart disease or a heart attack and can be a side effect of other diseases, such as diabetes. However, your blood pressure can temporarily rise due to stress, pregnancy, and even some common medications, including over-the-counter pain relievers and antidepressants. One high reading will not necessarily mean you have hypertension—but it’s good to keep vigilant.

Editor's note: This story was updated in July 2018 to reflect new blood pressure guidelines from the AHA.

From Cocaine to Chloroform: 28 Old-Timey Medical Cures

YouTube
YouTube

Is your asthma acting up? Try eating only boiled carrots for a fortnight. Or smoke a cigarette. Have you got a toothache? Electrotherapy might help (and could also take care of that pesky impotence problem). When it comes to our understanding of medicine and illnesses, we’ve come a long way in the past few centuries. Still, it’s always fascinating to take a look back into the past and remember a time when cocaine was a common way to treat everything from hay fever to hemorrhoids.

In this week's all-new edition of The List Show, Mental Floss editor-in-chief Erin McCarthy is highlighting all sorts of bizarre, old-timey medical cures. You can watch the full episode below.

For more episodes like this one, be sure to subscribe here.

Game of Thrones Star Sophie Turner Opened Up About Her Struggles With Depression

Helen Sloan, HBO
Helen Sloan, HBO

Playing one of the main characters on the most popular show currently on television isn't always as glamorous as it seems. Sometimes, the pressures of fame can be too much. Sophie Turner realized this while playing Sansa Stark on Game of Thrones, and has recently revealed how being in the public eye took a toll on her mental health.

Turner took on the role of Sansa Stark in 2011, when she was just a teenager, and she quickly became a household name. Now, at 23, she's come forward to Dr. Phil on his podcast Phil in the Blanks to explain how negative comments on social media affected her self-image and mental health.

"I would just believe it. I would say, ‘Yeah, I am spotty. I am fat. I am a bad actress.' I would just believe it," Turned explained. "I would get [the costume department] to tighten my corset a lot. I just got very, very self-conscious."

Later on, these feelings led to major depression. Turner developed a sense of isolation after she realized that all of her friends and family were going off to colleege while she was pursuing a sometimes-lonely acting career.

"I had no motivation to do anything or go out. Even with my best friends, I wouldn't want to see them, I wouldn't want to go out and eat with them," Turner explained. "I just would cry and cry and cry over just getting changed and putting on clothes and be like, 'I can't do this. I can't go outside. I have nothing that I want to do.'"

The feelings of depression stayed with Turner for most of the time she was filming Game of Thrones, and it's a battle she's still fighting. "I've suffered with my depression for five or six years now. The biggest challenge for me is getting out of bed and getting out of the house. Learning to love yourself is the biggest challenge," she continued.

The actress shared that she goes to a therapist and takes medication for her depression—two things that have helped her feel better.

Between Game of Thrones ending and planning her wedding to fiancé Joe Jonas, Turner may not have the time to take on many new acting roles in the near future. However, we'll continue to see her as Sansa Stark in the final season of Game of Thrones, and as Jean Grey in Dark Phoenix, which hits theaters on June 7.

[h/t: E! News]

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