Cardiovascular System

The cardiovascular system has a very important function ― getting oxygen and nutrients to your entire body and removing waste. Your cells depend on your cardiovascular system to get what they need to keep running smoothly. That’s why it’s vital to take care of your heart with exercise, a healthy diet and controlled blood pressure and cholesterol.


Drawing of heart and blood vessels in the body
Heart and blood vessels of the cardiovascular system

What is the cardiovascular system?

Your heart and many blood vessels in your body make up your cardiovascular system or circulatory system. Your heart uses the far-reaching, intricate network of blood vessels to deliver oxygen and other necessary things to your whole body. This network also removes the things your body doesn’t need and takes them to organs that can get rid of the waste. Your blood carries the oxygen, nutrients and waste through your entire body.


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What does the cardiovascular system do?

The function of the cardiovascular system is to make sure your body gets the oxygen, nutrients and other things it needs and gets rid of things it doesn’t.

Day and night, even while you’re asleep, your heart moves blood through your body. This is why your healthcare provider can hear your heartbeat. It’s the sound of your heart doing its job. Your heart circulates about 2,000 gallons of blood every day.

Some blood vessels (veins) bring blood to your heart, while others (arteries) carry blood away from your heart. Your blood vessels also take away waste (like carbon dioxide) from your cells.

Blood always follows the same route through your heart. Valves along the route make sure the blood is going the right way.

Two important circulation processes

Pulmonary circulation

Blood without oxygen comes into the right side of your heart and is sent to the lungs to get oxygen and get rid of carbon dioxide. Then the oxygenated blood comes back through the left side of your heart.

Systemic circulation

Blood that has just gotten oxygen from the lungs and returned through your heart’s left side is pushed out to the rest of your body’s cells so they can receive oxygen and nutrients. The cycle starts again when blood without oxygen goes to the right side of your heart.

How does the cardiovascular system help with other organs?

The cardiovascular system (your heart and blood vessels) supplies your body’s organs with oxygen and nutrients so your organs can do their jobs. Your blood vessels also carry carbon dioxide and other waste away for disposal.

Your cardiovascular system also helps your body:

  • Get what it needs during exercise, as well as during rest.
  • Keep your temperature at a normal level.



Where is the cardiovascular system located?

Your heart is located in the middle of your chest. It connects to your blood vessels. They go everywhere throughout your body so they can get oxygen and nutrients to every part of your body. They also take waste away from all the cells in your body.

What does the structure of the cardiovascular system look like?

Your heart is a very important part of your cardiovascular system because it powers the system that brings your cells what they need and takes away what they don’t. Your heart connects to a network of blood vessels all over your body.

If you’ve ever seen water or sewer pipes under the street, you know they are very large. These pipes lead to smaller and smaller pipes that carry water into your house and sewage out of your house. Similar to the main pipes under the street, the blood vessels going into and out of your heart are the largest in your body. They connect to smaller and smaller blood vessels as they get farther away from your heart to deliver oxygen and remove waste throughout your entire body. Capillaries, the tiniest of blood vessels, transfer oxygen, nutrients and waste between your blood vessels and your tissue cells.


How big is the cardiovascular system?

Your heart is about the size of your fist. Your blood vessels run throughout your body from top to bottom, so the network is as tall and wide as you.

How much does your heart weigh?

Gender and overall body weight, as well as disease, can affect your heart’s weight. But it’s estimated to be about 8 ounces to 12 ounces.

What is the cardiovascular system made of?

Blood vessels are made up of layers of connective tissue, muscle and elastic fibers. Your heart has muscle and other tissue. Blood flows through its four hollow chambers.

Conditions and Disorders

What are the common conditions and disorders that affect the cardiovascular system?

Many of the problems with the components of the cardiovascular system have to do with slowdowns or blockages in the blood vessels. Since your blood vessels supply your entire body with oxygen, a blockage in any of the blood vessels makes it harder to deliver that oxygen.

Common cardiovascular problems include these heart problems:

Other cardiovascular problems happen in your blood vessels, such as:

  • Aneurysm.
  • Stroke.
  • Atherosclerosis (plaque buildup in the arteries).
  • Vascular diseases (diseases involving blood vessels).

What are some common signs or symptoms of cardiovascular system conditions?

Signs of a heart problem include:

Signs of a stroke include:

  • Weakness in your arm.
  • Drooping in your face.
  • Speech that is hard to understand.

What are some common tests to check the health of the cardiovascular system?

Your healthcare provider can use tests that require the use of machines, but they’ll probably start by simply listening to your heartbeat with a stethoscope. Ways to check the health of your cardiovascular system organs include:

  • Electrocardiogram (EKG).
  • Blood tests.
  • Echocardiogram (using sound waves to make a picture of the heart and valves).
  • Stress tests (treadmill test, sometimes with imaging).
  • Cardiac CT (using X-rays and a computer to make cross-sectional images).
  • Positron emission tomography (PET) scan (detecting an injected radioactive drug that diseased cells absorb easily and making an image from that).
  • Cardiac MRI (a large magnet and radio waves create images).
  • Angiogram (heart catheterization).

Healthcare providers can use ultrasound to check your blood vessels.

What are some common treatments for the cardiovascular system?

Treatments for the cardiovascular system may be for your heart, your blood vessels or both. Treatments for cardiovascular system diseases include:

  • Medical procedures like angioplasty.
  • Surgery (like fixing a heart valve or putting in a pacemaker).
  • Medicines.
  • Lifestyle changes.


What can I do to help my cardiovascular system function well?

You can help keep your heart and blood vessels healthy in a number of ways, including:

  • Exercising regularly.
  • Controlling high blood pressure.
  • Controlling high cholesterol.
  • Quitting smoking and using tobacco products.
  • Eating heart-healthy foods.
  • Staying at a healthy weight.
  • Keeping your blood sugar at a normal level.

Additional Common Questions

Why is the cardiovascular system important?

Your heart and blood vessels, the parts of the cardiovascular system, are important because they bring oxygen, nutrients and other good things to every cell in your body. They also take away carbon dioxide and waste. This supply of nutrients and the removal of waste is the main function of the cardiovascular system.

What is the circulatory vs. cardiovascular system?

They are different names for the same system.

A note from Cleveland Clinic

Your cardiovascular system, which is made up of your heart and blood vessels, is a crucial part of your body. When your cardiovascular system is working right, the cells in your body get a continuous supply of oxygen and nutrients from your blood. Blood vessels also remove carbon dioxide and other waste. You have the power to keep your heart and blood vessels strong. Eating healthy foods, exercising, controlling your blood pressure and cholesterol and quitting smoking are all good for your cardiovascular system. Ask your provider to help you get heart healthy.

Medically Reviewed

Last reviewed on 09/13/2021.

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