Hypertension: The Silent Killer

One of the most common health conditions that goes unnoticed or dealt with is hypertension, that is why it has been given the name the “silent killer.” Hypertension is when the pressure inside the arteries is too high. Where the opposite, too low blood pressure, is called hypotension. Surprisingly, nearly one in every three people in the US are affected by it! Yet, unsurprisingly people rarely deal with it until it severely impacts their quality of life.

So why does blood pressure change? Blood pressure is affected by many things: heart rate and stroke volume, autonomic nervous system controlling the arteries, diet, activity, genetics, kidneys, and even hormones. Blood pressure goes up and down with every heartbeat as blood is pushed into the arteries and veins. In a healthy way, blood pressure goes up when exercise starts to force much needed blood into working muscles. The body achieves this by increasing heart rate, blood vessels dilating (widening) in the working muscle and constricting (narrowing) in other places in the body. When the heart pumps out more blood into the body where most of the arteries are smaller, the pressure goes up. Then, during rest, blood vessels dilate and the heart pumps slows to allow blood pressure to decrease. This change in blood pressure is healthy as long as it reacts with exercise. Blood pressure that is always high is unhealthy and called hypertension.

The rapid rise and fall of blood pressure is due to the control of the contraction and relaxation of arteries and the prompting the heart. Both stimulated by the baroreflex. Think of the baroreflex as a rubber band that stretches and shortens, thus can detect blood pressure in the carotid artery. When we breath slowly, opposite of exercise, it improves the sensitivity of the baroreflex. Since this reduces sympathetic activity (autonomic nervous system) and chemoreflex activation, breathing slowly (6x/min) can be a potentially robust reducer of hypertension along with many other benefits.

There are two types of hypertension, essential and secondary. With essential hypertension it is hard to find a direct cause, but if it is secondary hypertension a doctor can easily pinpoint the cause. Some types of secondary hypertension include: drugs (some types of illegal, prescribed, or over the counter), caffeine, unbalanced hormones or even kidney disease. Essential hypertension can be caused by a high sodium diet, a low potassium diet, diet low in fruits and vegetables, not getting enough sleep or even a sedentary lifestyle. For any reason, blood pressure that is constantly too high can put added stress on the heart, damage arteries and veins, increase risk for a stroke, and hurt kidneys.

The main controller of filtering out water (helping determine blood volume) is the kidneys. But if blood pressure falls due to a drop in blood volume, they release an enzyme called rennin. Rennin splits angiotensin and creates angiotensin 1. Then, through an angiotensin converting enzyme (ACE) it is split to make angiotensin 2 which causes vasoconstriction (narrowing of veins) and thus blood pressure rises. When blood pressure falls, aldosterone increases which causes an increase in water retention and blood volume through salt retention. On the other hand, when blood pressure is too high, atrial natriuretic peptides produced by the atrium of the heart cause kidneys to secrete sodium and inhibit aldosterone and renin.

Hypertension usually increases with age but a healthy lifestyle can mediate it. As people age, veins and arteries lose elasticity meaning they flex less with increases in volume and thus make the blood pressure even higher. It can make the pressure higher in both phases of the heart beating, systole and diastole (when the heart is contracting or relaxing). Another reason hypertension usually is associated with age is people usually gain weight. The body has to increase pressure veins and arteries in order to reach so much body mass. Small changes in weight can have large effects in blood pressure. If one of your goals is to lose weight to lower blood pressure, a good rule of thumb is that blood pressure decreases 1/1mm for every kilogram of weight loss (2.2lbs).

People use a variety of lifestyle changes to help decrease chronic high blood pressure. One method is to lower the amount of blood volume in the arteries and veins by pulling a little bit of water. This is most easily done by decreasing the amount of salt in the blood by way of decreasing the amount of dietary salt. Since salt pulls water to it through osmosis. People that intake low amounts of potassium, calcium or have multiple alcoholic drinks per day have been associated with high blood pressure. Non physiological factors that are correlated to hypertension are a lack of exercise, low educational achievement or low socioeconomic status.

Hypertension can be scary due to its low level of symptoms until a sufficient amount of damage has occurred. Some people can sense a difference if the change is sudden mostly likely do to suddenly starting or stopping medication. But some of the symptoms are: dizziness and unresponsiveness, headaches, vomiting, nosebleeds, blurred vision, chest pain and even shortness of breath. It has even been associated with form of dementia. If you feel any of these you need to stop what you are doing, do not eat or drink right away, lie down and seek medical help if necessary.

I recommend people understand their blood pressure and talk to their doctor about it at their yearly physical. Understanding that you have hypertension can go a long way in identifying if you have related symptoms. Getting ahead of preventable sickness and disease is the key to having abundant strength. Most people keep their blood pressure healthy by not eating too much salt, maintaining a proper body weight, exercising regularly and not consuming too much alcohol. Other things that can help decrease blood pressure are to get off medication and drugs including smoking, by breathing slowly and by managing stress.

Normal blood pressure (systole/diastole): less than 120/80

Prehypertension: 120-139/80-89

Hypertension (Stage 1): 140-159/90-99

Hypertension (Stage 2): more than 160/100

For more information on the prevalence of hypertension and how much of a silent killer it really is, click here.