High Blood Pressure

What is High Blood Pressure (Hypertension)?

Blood pressure is the force of blood pushing against your artery walls as it flows through your heart. It is determined by the amount of blood pumped by your heart and the amount of resistance to blood flow in your arteries. Therefore, the narrower your arteries are and the more blood your heart pumps, the higher your blood pressure will be.

Arteries carry oxygen-rich blood from the heart to the rest of the body. If you have high blood pressure (or hypertension), it will eventually lead to more serious health problems, including heart disease.

What are the symptoms of high blood pressure or hypertension?

Unfortunately most people with hypertension, even those with dangerously high levels, have no signs or symptoms. A few people may suffer from headaches, shortness of breath or nosebleeds. However these signs may not result until hypertension has reached a life-threatening stage.

Around 4 million Australians suffer from hypertension and of these, more than two thirds have uncontrolled or unmanaged high blood pressure.

What are the types of different hypertension (high blood pressure)?

There are two types of hypertension:

  • Primary (essential) hypertension
  • Secondary hypertension

What are the causes of hypertension (high blood pressure)?

Each type of hypertension has different causes.

Primary (essential) high blood pressure usually develops gradually and in most cases, there is no known cause.

Secondary hypertension is caused by an underlying condition and generally appears suddenly, causing higher blood pressure than primary hypertension. Some conditions which may lead to secondary hypertension include:

  • Obstructive sleep apnoea
  • Kidney problems
  • Adrenal gland tumours
  • Thyroid problems
  • Defects in blood vessels that you are born with
  • Certain medications such as birth control pills, cold remedies, congestants, over-the-counter pain relievers, some prescription drugs
  • Illegal drugs
  • Alcohol abuse or chronic alcohol use

How is high blood pressure diagnosed?

Measuring blood pressure is very straightforward and can be done with your doctor. Your doctor will place an inflatable cuff around your arm and use a pressure measuring gauge. The reading has two numbers. The first number (systolic pressure) measures the pressure in your arteries when your heart beats. The second (diastolic pressure) measures the pressure in your arteries between beats.

The measurements fall into four general categories:

  • Normal blood pressure: A normal reading is below 120/80 mm Hg
  • Prehypertension (Elevated): A systolic pressure ranging from 120 to 129 mm Hg or a diastolic pressure ranging from 80 to 89 mm Hg. Prehypertension tends to get worse over time
  • Stage 1 hypertension: A systolic pressure ranging from 130 to 139 mm Hg or a diastolic pressure ranging from 80 to 89mm Hg
  • Stage 2 hypertension (Severe hypertension): Stage 2 is a systolic pressure of 140 mm Hg or higher or a diastolic pressure of 90 mm Hg or higher
  • Blood Pressure Crisis - Call Doctor! - Systolic pressure readings of over 180 mm Hg or a diastolic pressure of 120 mm Hg or higher, require urgent attention

Before being diagnosed with high blood pressure, your doctor will take two to three readings as it can vary throughout the day. A ‘normal’ blood pressure reading will also consider your overall risk for heart disease, which is based on your medical history. For example, your doctor might aim to treat your blood pressure more aggressively if you have had a prior heart attack or have several risk factors for heart disease.

This is one of the checks that is done on our mobile Heart Health Check Tour, along with high cholesterol and blood sugar level checks.

How can hypertension (high blood pressure) be treated?

Lifestyle changes are an important way to control hypertension. These include:

However if lifestyle changes are not enough to manage hypertension, doctors may prescribe the following medications:

  • Thiazide diuretics
  • Beta blockers
  • Angiotensin-converting enzyme (ACE) inhibitors
  • Angiotensin II receptor blockers (ARBs)
  • Calcium channel blockers
  • Renin inhibitors

Additional medications also used to treat hypertension include:

  • Alpha blockers
  • Alpha-beta blockers
  • Central-acting agents
  • Vasodilators
  • Aldosterone antagonists

How can hypertension (high blood pressure) be prevented?

If your hypertension is hereditary, it is important to combine a healthy lifestyle with the appropriate medication recommended by your doctor, in order to keep it under control. Ultimately, leading a healthy lifestyle is the best way to reduce or prevent hypertension, including:

Ask your doctor for a heart health check which looks at the key risk signs. Download our Heart Health Check Guide to take with you to your next doctor's appointment.

Research into High Blood PressureDonate to heart researchHow to prevent heart diseaseLearn about other heart diseases

Acknowledgement of Country

The Victor Chang Cardiac Research Institute acknowledges the traditional custodians of the land, the Gadigal of the Eora nation, on which we meet, work, and discover.
Our Western Australian laboratories pay their respect to the Whadjuk Noongar who remain as the spiritual and cultural custodians of their land.