High blood pressure, or hypertension, is often called “the silent killer”, and for good reason. There are no obvious symptoms, so if you have it you likely won’t even know unless you get checked. That’s not to say it’s harmless – quite the opposite. Hypertension can do damage to the body slowly over years and is a major risk factor for a variety of serious medical conditions.
According to the Heart and Stroke Foundation, nearly one in five Canadians has high blood pressure, but only 66% of these people have it under control, and 17% don’t even know they have it. It’s important to get checked, especially if you’re older, overweight, or sedentary. By learning about the dangers that it can cause and the unhealthy choices that can make it worse, the risks of hypertension can be mitigated and controlled.
What causes high blood pressure?
Many risk factors for hypertension are caused by lifestyle choices. Some of these factors include a lack of physical activity, a diet high in fats and sodium, and being overweight or obese. These all contribute to a weak heart and high cholesterol, which raises blood pressure and narrows arteries. Other choices such as smoking and alcohol consumption have also been shown to be associated with high blood pressure. High stress levels can also contribute.
Some other causes of high blood pressure are beyond the control of the individual. Hypertension becomes more common with age, so older adults are at greater risk. Those who have a family history of high blood pressure are also at greater risk of developing it themselves. Additionally, blood pressure levels vary by race and ethnicity.
What does high blood pressure do?
Damages arteries – Normally, arterial walls are smooth and flexible. When blood pressure increases, this can cause a condition called atherosclerosis which causes arteries become narrow and stiff. This happens when high blood pressure causes small tears on the arterial walls, and these tears collect a build-up of plaque consisting of substances like fats and cholesterol. This narrows the arteries and makes it more difficult for blood to flow, which causes the heart to pump harder. Weakened arterial walls can also lead to aneurysms, which can be lethal if they occur in the heart or brain.
Enlarges and weakens the heart – As the heart pumps harder to compensate for narrowed arteries, this causes it to become enlarged. This commonly occurs in the left ventricle, which is responsible for pumping blood to the rest of the body. Plaque buildup in the coronary arteries can also make it more difficult for oxygenated blood to flow back into the main heart muscle. This is known as coronary artery disease; it weakens the heart and can also lead to a variety of other complications.
What are the effects of high blood pressure on the body?
Heart – Damage to the heart can’t be healed, so a weak heart is at risk for serious issues. Heart attacks occur when the flow of blood to the heart muscle becomes blocked. This can happen if a clot forms on the surface of plaque buildup in the coronary arteries and blocks blood flow. Heart failure is also common in individuals with hypertension and coronary artery disease. As the heart has to work harder to pump blood, over time this causes the heart to become weak, wear out, and fail.
Brain – A stroke occurs when the brain doesn’t get enough oxygenated blood and brain cells start to die. Hypertension is a major risk factor for ischemic strokes which cut off blood flow to the brain. These can be caused by blockages and clots in the brain’s blood vessels. Reduced blood flow to the brain is also a risk factor for cognitive disorders like dementia.
Eyes – High blood pressure can damage blood vessels inside the eyes. If the vessels supplying blood to the retina get damaged, this can cause retinopathy, which can lead to blurred vision or even vision loss. Damage to the optic nerve can occur as well, and this can also lead to vision problems.
Kidneys – Hypertension can cause damage to the arteries leading to the kidneys as well as the small blood vessels inside them. If these become damaged, this can hamper the body’s ability to filter waste from the blood. This can lead to kidney failure and may require dialysis or a kidney transplant.
Peripheral arteries – Peripheral artery disease refers to a narrowing of arteries in areas other than the heart or brain. It most commonly occurs in the legs but can affect other areas as well. The disease can cause pain, skin problems, and numbness, and in serious cases may develop an infection.
Bones – High blood pressure is a risk factor for bone loss or osteoporosis. It has been shown to increase the amount of calcium excreted by the body through urine, which contributes to weaker bones.
Sexual organs – Hypertension can cause sexual dysfunction, as decreased blood flow to the genitals can result in erectile dysfunction in men and decreased libido in women.
Hypertension is a major risk factor for these serious medical conditions if left untreated. However, with proper lifestyle choices, blood pressure can be lowered and kept at healthy levels. For most people, a healthy blood pressure should have a systolic pressure below 120, and a diastolic pressure below 80. If you don’t know what your blood pressure is, you should get checked, especially if your lifestyle or genetics put you at risk.