What do we mean by high blood pressure?
It is estimated that half of adults in the US have high blood pressure. This is currently defined by the American Heart Association as a systolic blood pressure of 130 mmHg over a diastolic pressure of 80 mmHg (also expressed as 130/80).
The systolic blood pressure refers to the pressure in your arteries when the heart is pumping blood. The diastolic blood pressure refers to the pressure in your arteries when the heart is relaxed between beats.
Transiently, it is normal to have a raised blood pressure as a physiologic response - think about that bit of stress at work, a surprise moment, or from doing exercise. However, chronically high blood pressure or hypertension is a major problem,as long term strain on your arteries impacts their structure and compromises blood flow to organs e.g. in heart disease or stroke - two of the top five causes of death in the US.
The best way to check if you have hypertension is to do repeat blood pressure readings at different times while you are at rest. Pharmacies often offer a free blood pressure check if you do not own a monitor. Consult your doctor if you have chronic hypertension; they may do further tests and give you advice.
Why is high blood pressure a problem?
Several organs can be affected by high blood pressure and the long term insidious damage it causes. Notably the vascular system, heart, brain, kidneys and eyes can be affected.
Healthy arteries are robust and elastic with smooth inner walls. Chronic strain on your arteries can cause damage, narrowing, blockage or aneurysms. Damage occurs when the high pressure of the blood disrupts the smooth lining of the arteries. Narrowing can occur as cholesterol from the fat in your food can deposit under the damaged lining more easily. This makes arteries less elastic. The narrowing may become a complete blockage if the deposits grow or if blood clots due to the disruption of the flow of blood. Aneurysms refer to a weakening of the artery walls such that the artery ‘balloons out’. This is particularly dangerous in larger arteries (e.g. aorta) as aneurysms can burst leading to internal bleeding.
Hypertension can cause coronary heart disease whereby the arteries supplying the heart muscle are narrowed. You are leaving yourself prone to angina, heart attacks and irregular heart rhythms. High blood pressure can therefore also lead to congestive heart failure in the long term, where the heart muscle is weakened and cannot cope with the demands of the body, this can lead to failure of your organs and death.
Strokes and vascular dementia risk is raised in high blood pressure. Strokes can be due to narrowing of the arteries due to atherosclerosis or blood clots as described earlier meaning that brain cells fail to receive enough oxygen and begin to die. Strokes can be lethal and highly debilitating affecting speech, motor function and sensory function depending on the part of the brain affected. Narrowing of vessels and stroke both contribute to a form of dementia called vascular dementia in which there is progressive neural degeneration.
The kidneys can fail, scar or have an aneurysm due to high blood pressure. Your kidneys function to remove waste from your body. Fluid and waste can accumulate in your body if your kidneys are not working well and you may need regular dialysis.
The blood vessels in your eyes and the optic nerves are at risk in high blood pressure. Blurred vision, distorted vision or loss of vision may result. Fluid may also accumulate near the retina again leading to a loss of vision and possible scarring.
Hypertension can cause erectile dysfunction as the vessels supplying the penis are fine and easily damaged.
Management of high blood pressure
Thankfully hypertension is largely manageable and its consequences are preventable. So while older age, your ethnicity and genetics may play a role you have the power to limit hypertension through a good lifestyle. By this we mean:
- Keeping a healthy weight
- Following a diet rich in fruit and vegetables but low in sugar
- Limiting salt in meals
- Reducing alcohol and caffeine
- Sleeping adequately
- Getting screened for sleep apnea
Remember to take your blood pressure medication if prescribed. Always contact your doctor regarding symptoms and medication if you have any concerns.