What is heart failure?

Heart failure is a disorder in which the heart cannot pump enough blood to meet the needs of the body.

The healthy heart

To understand heart failure, it is helpful to know how a healthy heart works. The heart is a muscular hollow organ about the size of your fist that beats around 100,000 times every day. Its main job is to pump the right amount of blood to all parts of the body. The circulating blood brings oxygen and nutrients to the tissues and removes waste products.

During a heartbeat, the heart first contracts, pushing blood out towards the rest of the body; it then relaxes, filling up with returning blood. How quickly and forcefully the heart pumps depends on the needs of the body. During exercise, the heart must work harder to keep the muscles and organs supplied with all the oxygen-rich blood they need.

Inside the heart are four chambers: Two on the left side and two on the right. Blood enters the heart and flows into the upper chambers (left and right atria). From here it is pushed into the lower chambers (left and right ventricles). The ventricles then contract, forcing blood out of the heart.

The left and right sides of the heart have different roles, and are often known as the ‘left’ and ‘right’ circulations. The right circulation takes deoxygenated blood that has already traveled around the body and pumps it to the lungs to pick up fresh oxygen. The left circulation takes this newly oxygenated blood and pumps it back out to the rest of the body.


The heart and its location in the body

The failing heart

In people with heart failure, the heart pumps less efficiently than normal. In the early stages of heart failure, the heart may still be able to meet the body’s needs. People suffering from heart failure may notice symptoms only during exercise, or not at all. But over time the heart can gradually become worse and pump less effectively. As a result, the tissues and organs of the body do not receive as much oxygen-rich blood as they need. Blood and fluid also backs up and builds up in certain body tissues and organs. This is known as “congestion”.

Heart failure tends to develop gradually over many years. In its mildest form it may have little effect on a person’s life, but when it is severe, heart failure can lead to hospital admissions and even death. Because heart failure is a lifelong condition that often worsens over time, it is important to start treatment as soon as possible. With the right treatment and care, people with heart failure can lead full and active lives.

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