Sometimes when I’m desperately trying to fall asleep I instead think of all the things that might kill me. Alligators, drunk drivers, hurricanes, and running out of cookies usually top the list. Do you know what doesn’t top the list? High blood pressure. It really should though. High blood pressure is a leading preventable cause of premature death, affecting well over a billion people worldwide and causing upwards of 9 million deaths a year. Maybe the alligators can chew on those facts for a while. So what is high blood pressure, why is it such a big deal, why do we get it, and what can we do?

High blood pressure is exactly what it sounds like; when the blood in your arteries is being forced through more strongly than normal. The medical name for high blood pressure is hypertension. Hyper– means over or above, and -tension, in this case, indicates the stress of your arteries. Hypertension is excessive stress on your arteries.  Blood pressure can be split into two numbers, systolic and diastolic. These refer to the action of the heart, where systolic is the contracted, pumping blood pressure, and diastolic is the relaxed blood pressure. When you get your blood pressure checked, these are reported as two numbers “over” each other. A reading of 140/90 mmHg or higher is high blood pressure, but there is an increased risk of complications with blood pressure above 120/80 mmHg.

High blood pressure is particularly dangerous. It is easy to see why: the bloodstream is how we deliver oxygen to the cells, and it touches every cell in the entire body. Two of the biggest dangers with elevated blood pressure are ischemic heart disease and stroke, conditions where the blood supply doesn’t reach the heart or brain. High blood pressure can also cause brain bleeds, chronic kidney damage, and other types of heart damage. All of these organs are vital to our survival, so a condition that potentially damages all of them is life-threatening. 

What are the causes of high blood pressure? High blood pressure is calculated the same as in any pipe at its most basic level. The amount of blood coming out of the heart is counteracted by the resistance from the arteries. More output or more resistance makes blood pressure rise. High blood pressure on its own isn’t bad, it’s adaptive for critical situations. When we see a lion and it charges us, we become stressed and initiate the sympathetic nervous system, also known as fight, flight, and freeze. Part of this system’s job is to constrict blood vessels and raise the heart rate to deliver large amounts of oxygen to cells. We see damage when we have high blood pressure for long amounts of time. Some body systems that cause prolonged elevations in blood pressure are:

• Kidneys regulate the volume of blood in veins, using urine to get rid of extra fluid
• Blood vessels can constrict and dilate to regulate resistance. They can also stiffen, lose muscle, and become inflamed or damaged
• The brain activates the kidneys and blood vessels. Constant stress or disorders can keep them active for too long and keep blood pressure high
• Inflammation is caused by inflammatory cells and hormones, including angiotensin, which can accumulate (sometimes due to salt) in blood vessels and the kidney
• Several other systems and mechanisms are at play, including genetics, the microbiome, and reactive oxidative stress

These are the major players in primary or essential hypertension. Secondary hypertension is caused by another identifiable disease, like kidney disease.

So what can we do? Some outcomes depend on things we can’t easily change, like access to quality healthcare and blood pressure medication. Many lifestyle options can be changed to improve our blood pressure:

• Relax! Lowering stress has many positive effects, including lowering blood pressure as well as the feelings of not being stressed (being not stressed is recommended).
• Alcohol has mixed results. Consuming a small amount corresponds to lower blood pressure, but there isn’t great evidence of it causing lower blood pressure. Avoid excessive drinking.
• Physical activity can have big effects. Even a daily light walk can reduce hypertension.
• Obesity has a direct, linear relationship with blood pressure. For each kilogram (~2.2 pounds) you lose, blood pressure decreases by around 1 mmHg.
• Diet can be hard to change, but can also affect blood pressure.
  • Avoid: red and processed meats, sweetened foods, saturated and trans fats
  • Consider eating: fruits and veggies, nuts and seeds, lean dairy, vegetarian and mediterranean diets
• Sodium (salt) intake matters:  salt directly affects how much fluid is in the bloodstream. The average person consumes almost 4000 mg of sodium per day, the recommended amount is under 2300 mg. Though lowering sodium decreases blood pressure, studies are mixed with regard to heart disease outcomes
• Potassium acts in direct opposition to sodium. Increasing the amount of potassium can lower blood pressure – don’t go too crazy, though! Extreme amounts can slow or stop the heart (stopping your heart is not recommended).

Even though we have good evidence for lifestyle changes lowering blood pressure, the biggest difference between countries in terms of controlling blood pressure is access to medicine. Blood pressure medicines have saved countless lives and helped stem the blood tide of hypertension. There are several types of blood pressure medicines on the market. Diuretics get rid of sodium and water in the blood. Angiotensin-converting-enzyme (ACE) inhibitors and Angiotensin-receptor blockers (ARB) help ease inflammation, relax the blood vessels, and keep them from constricting. Calcium channel blockers reduce heart rate. These all have side effects, but the biggest challenge with them is that they are daily oral medications, which can be forgotten, missed, or hard to adhere to. Longer-term solutions are in clinical trials and may be available to you if you qualify. So don’t sleep on your high blood pressure. Check with your local ENCORE Research office to see what studies are enrolling. See ya’ later, alligators!

Staff Writer / Editor Benton Lowey-Ball, BS, BFA

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Sources:

Harrison, D. G., Coffman, T. M., & Wilcox, C. S. (2021). Pathophysiology of hypertension: the mosaic theory and beyond. Circulation research, 128(7), 847-863. https://www.ahajournals.org/doi/full/10.1161/CIRCRESAHA.121.318082 

Lifton, R. P., Gharavi, A. G., & Geller, D. S. (2001). Molecular mechanisms of human hypertension. Cell, 104(4), 545-556. https://doi.org/10.1016/S0092-8674(01)00241-0

Mills, K. T., Stefanescu, A., & He, J. (2020). The global epidemiology of hypertension. Nature Reviews Nephrology, 16(4), 223-237. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7998524/