High blood pressure is one of the major risk factors for heart disease, kidney disease and stroke, the leading causes of death worldwide. Learn what high blood pressure is, why it’s bad, what causes it, how it is treated, and more.
What is High Blood Pressure and Why is it Bad?
High blood pressure, or also known as hypertension, is when your blood pressure is consistently too high. Blood pressure is the pressure or force of blood against the walls of your arteries.
The only way to know whether your blood pressure is too high or not is to have it measured. Normally, blood pressure is measured in millimeters of mercury (mm Hg) and is recorded as two numbers.
The first or top number is called systolic blood pressure, which represents the pressure in the arteries when your heart beats and pumps blood. The second or bottom number is called diastolic blood pressure, which represents the pressure of the blood when your heart rests in between beats.
For example, a blood pressure measurement of 120/80 mmHg means that systolic blood pressure is 120 mmHg and diastolic pressure is 80 mmHg.
As a general guide:
- Normal blood pressure is below 120/80 mmHg
- Prehypertension is between 120/80 mmHg and 139/89 mmHg
- High blood pressure is considered to be 140/90 mmHg or higher (or 150/90 mmHg or higher if you’re over the age of 80)
If your blood pressure is too high, it puts extra strain on your blood vessels, heart and other organs, such as the brain, kidneys and eyes.
What Causes High Blood Pressure?
The causes of high blood pressure can be divided into two major types: primary hypertension and secondary hypertension.
Primary hypertension, also called essential hypertension, is the most common type of high blood pressure, accounting for 90-95% of all cases. This type of blood pressure usually takes many years to develop. It has no clearly identifiable cause, but you are at higher risk of developing it if you:
- Are over age 55
- Are African American
- Are overweight or obese
- Have a family history of high blood pressure
- Don’t get enough exercise
- Eat too much salt
- Drink too much alcohol
Secondary hypertension is high blood pressure that is caused by another medical condition. But it rare to occur, only about 5-10% of hypertension cases are thought to result from secondary causes. Some of the common causes of secondary high blood pressure include:
- Kidney disease
- Thyroid problems
- Obstructive sleep apnea
- Disorders of the adrenal gland (such as pheochromocytoma or Cushing syndrome)
- Certain medications such as birth control pills, diet pills, decongestants, stimulants, and steroids
What are the Signs and Symptoms of High Blood Pressure?
Most people with hypertension are unaware of the problem because it shows no warning signs or symptoms. For this reason, hypertension is often called ‘the silent killer’. However, when symptoms do appear, they may include the following:
- Nausea and vomiting
- Vision problems
- Shortness of breath
- Heart palpitations
How is High Blood Pressure Diagnosed?
Since high blood pressure does not usually produce any symptoms, so you should have your blood pressure checked regularly, ideally once a year. Healthy adults aged over 40 should have it checked at least once every 5 years.
To determine if you have high blood pressure, your health provider may want to take blood pressure measurements on a few separate occasions. This is because your blood pressure normally changes throughout the day.
Generally, if you have a blood pressure reading taken on 3 separate occasions that is greater than 140/90 mmHg, then you have high blood pressure.
Your GP might suggest ambulatory blood pressure monitoring, where you’re attached to a small blood pressure machine which takes your blood pressure at regular intervals throughout the day and night.
This is usually done so that your doctor can get a better idea of what your usual blood pressure is when in a more relaxed setting, and to see what happens at different times of the day.
Your doctor may also ask you questions about your general health and if you have a family history of high blood pressure, diabetes, stroke, or heart problems. Some people may need to have a blood test or urine test.
How is High Blood Pressure Treated?
Hypertension can be successfully treated with lifestyle changes and medications. The type of treatment you have will depend on several factors, including:
- How high the blood pressure is
- The risk of cardiovascular disease or a stroke
For slightly high blood pressure, your doctor may suggest making lifestyle changes including:
- Reducing your salt intake to less than 6 grams a day.
- Eating a low-fat, balanced diet filled with plenty of fresh fruits, vegetables, and whole grains.
- Getting regular exercise – at least 150 minutes of moderate intensity physical exercise a week.
- Maintaining a healthy weight or losing weight if you’re overweight.
- Limiting the amount of alcohol you drink – no more than one drink per day for women and two drinks per day for men.
If blood pressure is high, they will recommend medication. The category of medication your doctor prescribes depends on your blood pressure measurements and your other medical problems. Medicines used to treat high blood pressure include:
- ACE inhibitors
- Angiotensin II receptor blockers (ARBs)
- Alpha-blockers (Doxazosin)
- Calcium-channel blockers
Most people need to take more than one type of medicine to lower their blood pressure, and research suggests that taking two or more medicines often has a much better effect than taking just one.