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Circulatory system

7-minute read

Key facts

  • The circulatory system is made up of the heart, lungs and blood vessels working together.
  • The role of the circulatory system is to move nutrients, hormones, oxygen and other gases to your body's organs, muscles and tissues, to use for energy, growth and repair.
  • Heart disease, stroke and high or low blood pressure, are common circulatory system conditions.
  • A healthy diet and up to 30 minutes of exercise daily, can help improve your heart health.

What is the circulatory system?

Your circulatory system, also called the cardiovascular system or vascular system, moves oxygen, nutrients and hormones to your body's cells to use for energy, growth and repair. Your circulatory system also removes carbon dioxide and other waste products that your cells do not need.

These key parts of your circulatory system maintain blood flow to all the cells in your body, so you can survive:

  • blood — made up of red and white blood cells, plasma and platelets
  • the heart — a muscular organ that pumps blood to all parts of your body
  • blood vessels, include arteries, capillaries and veins to carry blood pumped by your heart
Illustration showing the circulatory system.
Illustration showing the circulatory system.

How does my circulatory system work?

Blood that is low in oxygen collects in your heart's right atrium, one of the heart's 4 chambers. It moves into the right ventricle, which pumps this blood to your lungs where your red blood cells pick up oxygen and get rid of carbon dioxide. You then exhale the carbon dioxide.

The oxygen-rich blood returns to your heart's left atrium, then into your left ventricle. The left ventricle pumps oxygen-rich blood through your aorta, into your arteries, then to all parts of your body. Along the way, the blood gathers food nutrients from your small intestine.

As it enters the capillaries, your blood makes contact with tissues and cells. It delivers oxygen and nutrients and removes carbon dioxide and waste. Now low in oxygen, the blood travels through the veins to return to your heart's right atrium, where the circuit starts all over again.

What are the common health conditions of the circulatory system?

Cardiovascular disease

Cardiovascular disease (CVD) is all diseases of the heart and blood vessels.

Most CVD happens when fatty substances, called plaque or atheroma, build up in the lining of blood vessels. This causes the blood vessels to become narrow over time. Less blood is then able to pass through. This process is called atherosclerosis.

Atherosclerosis can cause coronary heart disease and ischaemic heart disease. Reduced blood supply means less oxygen and nutrients available to the heart muscles. This can cause angina or a heart attack, which needs emergency medical attention. The most common symptom of heart attack or angina is chest pain.

When the supply of blood to part of the brain is interrupted because of a blocked or burst artery, this results in a stroke. A stroke is also an emergency and will need urgent medical treatment.

Read more about heart problems and cardiovascular health here.

High or low blood pressure

When your heart pumps blood into your arteries, the blood pushes against the artery walls. This is what gives you your blood pressure reading. Blood pressure is measured in units called 'millimeters of mercury' (written as mmHg). Most doctors consider that a healthy blood pressure is higher than 90/60mmHg and lower than 140/90mmHg.

High blood pressure, also known as hypertension, can increase your risk of cardiovascular disease. It is the most common health problem of the circulatory system.

Low blood pressure, also known as hypotension, is a sign of good health for some people but can be a problem for others. Symptoms of low blood pressure include dizziness or fainting.

When should I see my doctor?

The best way to know how healthy your circulatory system is, is by seeing your doctor for a heart health check. Heart health checks should take around 20 minutes and if you're eligiable, are covered by Medicare.

The earlier cardiovascular disease is found, the earlier it can be treated and managed. If you have high blood pressure, it is especially important to have regular heart health checks with your doctor.

Low blood prepssure is only a problem if it has negative effects on how your body works, or how you feel. See your docotor if you have symptoms, for example, if you feel:

  • lightheaded
  • unsteady
  • dizzy
  • your vision is blurry
  • faint

How do I prevent cardiovascular problems?

There are some risk factors that cannot be changed when it comes to cardiovascular health like increasing age, family history or ethnic background. However, you can help improve your heart health and decrease the chance of cardiovascular disease.

A few ways to help reduce your risk include the following:

Resources and support

Speak with your doctor about any concerns you have about your heart health. There are a lot of resources and support online, visit any of the links below for further information:

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: August 2023

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