Hypertension

Over a billion people around the world have hypertension, or high blood pressure, so that pretty much means it’s pretty common. 

Let’s start by defining it. Typically, it’s represented by two numbers: the top number is the systolic blood pressure, which is the arterial pressure when the heart’s contracting; and the lower number is the diastolic blood pressure, which is the arterial pressure when the heart’s relaxing or refilling. Most of the time, blood pressure is taken in the brachial artery in your upper arm, because if the pressure is high there, it’s probably high throughout all of the arteries.

The guidelines for categorizing blood pressure have recently changed to reflect a growing body of evidence that shows that even moderately high blood pressures can significantly increase your risk for developing heart disease. Now, ‘normal’ systolic blood pressure is defined as less than 120 mmHg, and a normal diastolic pressure is less than 80 mmHg. Elevated systolic blood pressure is considered between 120 and 129 mmHg and less than 80 mmHg on the diastolic side. Stage 1 hypertension is between 130 and 139 mmHg on the systolic side, and between 80 and 89 mmHg on the diastolic side. Stage 2 hypertension is defined as anything that is 140 mmHg or higher on the Systolic side and 90 mmHg or higher on the diastolic side.

Typically, both systolic and diastolic pressures tend to climb or fall together, but that’s not always the case. Sometimes, you can have systolic or diastolic hypertension, when one number is normal and the other is really high. This is referred to as isolated systolic hypertension or isolated diastolic hypertension. 

High blood pressure is a serious problem for the blood vessels because it causes wear and tear on the endothelial cells that line the inside of the blood vessels. Just like a garden hose that’s always under high pressure, in the long term, blood vessels can develop tiny cracks and tears that can lead to serious problems, like myocardial infarctions, aneurysms, and strokes.

Now, about 90% of the time, hypertension happens without a clearly identifiable underlying reason. We call this primary hypertension, or essential hypertension. In other words, over time, pressure in the arteries starts to silently creep up.  And there are a bunch of risk factors that we’ve identified for primary hypertension. And these include: old-age, obesity, salt-heavy diets, and sedentary lifestyles.