Many people tell me they don’t care if they have a heart attack, but they sure don’t want a stroke. I suspect this is because the results of a stroke are often more debilitating than the results of a heart attack.

Whatever you feel about that way of thinking, it is clear that a stroke can be devastating. Fortunately, the risk of having a stroke has declined quite a bit: 40-50 percent from 1972 to 1994 and about 30 percent since 1995. This is primarily due to improvement in blood pressure control.

Unfortunately, in recent years the risk of having a stroke has not gone down any further. Why might that be? One of the biggest reasons is that up to half the people with hypertension do not have their blood pressure under control.

What is Blood Pressure?

Each time your heart pumps, it sends a jet of blood outward to the body which raises the pressure in the blood vessels. This is the top number of a blood pressure measurement, also called the systolic blood pressure. When the heart relaxes, the pressure starts to fall. The lowest level it reaches is called the diastolic pressure.

Several factors affect the pressure in the blood vessels. These including how often the heart pumps, how hard it squeezes, the size of the blood vessels, and the amount of blood in the vessels.

Imagine a water pump that is cycling on and off. When it turns on and begins to pump, the pressure begins to rise; the highest pressure it reaches is the same as your systolic blood pressure. When it cycles off the pressure gradually drops and the longer it stays off, the lower it goes. This is similar to your diastolic pressure.

Now imagine that the pump is pumping a large amount of water with a lot of force into a very small diameter pipe: the pressure in the pipe will be very high. If you imagine the opposite, a small amount of water pumped with very little force into a pipe with a giant diameter, the pressure will be very low. To change the pressure in the system, you can alter any of these factors individually (how hard the pumping action is, when it cycles on and off, the size of the pipes or the amount of water being pumped). At a very basic level, this is how your blood pressure works and this is how medications control blood pressure.

So, What is Hypertension?

We recognize a range of blood pressures, from normal, to pre-hypertension, to borderline and finally to hypertension. Normal is generally defined as less than 120mmHg (millimeters of mercury – a measure of pressure). However, the risk of dying is lowest at untreated blood pressures between 100 and 110mmHg (note, this is not the same as the goal we use when treating blood pressure). A person’s blood pressure is too high when it hits 140mmHg, or when the diastolic blood pressure is more than 90mmHg.

Why is Hypertension a Concern?

There are many potential consequences to leaving hypertension untreated. I already mentioned the one many fear most: stroke. Hypertension is also associated with vascular dementia, aneurysms (ballooning of the arteries, which can then rupture), heart attacks, kidney failure leading to dialysis, dysfunction, and congestive heart failure. Unfortunately, unless your blood pressure is extremely high, you can’t feel it (though some insist otherwise). Consequently, people aren’t aware of how high their blood pressure is… until they are, and then, it’s too late.

What Factors Cause Hypertension?

Being either overweight or obese is one of the strongest risks for hypertension. Sodium, usually from table salt and processed foods, especially in excess of 3000mg daily increases the risk. Physical inactivity, diabetes, race and family history increase the risk. However, family history only increases risk by about 30 percent. Personality traits such as impatience and hostility are associated with an increased risk.  Depression is also a risk for high blood pressure.

A partial list of other causes includes sleep apnea, certain medications such as chronic use of nonsteroidal anti-inflammatory drugs (NSAIDS such as ibuprofen or naproxen), certain anti-depressants, decongestants, some weight loss medications, and amphetamines. Illicit drugs such as cocaine and methamphetamines can also cause hypertension.

How Do We Treat Hypertension?

In one sense, your actions matter little provided you have your blood pressure under control. However, plenty of caveats apply for people with very specific problems such as kidney disease, heart failure, or coronary artery disease, among others. At a basic level, the most important things you can do are to increase physical activity, lose weight, and avoid sodium.

Some evidence indicates yoga can help. Meditation may also help, though the evidence for this is not very strong. On the other hand, it certainly won’t hurt and may help with other aspects of living.

Lifestyle changes are always part of the treatment no matter how high the blood pressure. Depending upon the level of the pressure, medications become critical to controlling blood pressure for many if not most. Remember that the number of strokes has declined primarily because of the medical treatment of blood pressure.

Once hypertension develops it is generally permanent. That’s why constant monitoring is so important, regardless if high blood pressure is controlled with lifestyle changes or with medications.

R. Mark Burke, MD, FACC, is former member of the BMH medical staff.