Your heart sits in your lower chest, on the middle-left. It’s about the size of a clenched fist.
The heart’s job is to pump blood round your body, delivering the oxygen and nutrients your body needs to be healthy and work properly.
A normal heart has 2 sides - left and right, separated by a muscular wall. Each side has 2 chambers:
Valves control the direction the blood flows between atrium and ventricle.
The left side of your heart pumps blood out around your body to deliver oxygen and nutrients.
When the blood comes back to your heart after travelling round your body, it’s low in oxygen. Your heart’s right side collects the returning blood, and pumps it to your lungs to collect oxygen. The oxygen-rich blood is then sent to the left side to start the process again.
The left ventricle is bigger than the right, because it has to pump blood further round the body.
The heart’s pumping is controlled by special fibres that send electrical signals to the chambers.
Blood is pumped around your body through a network of blood vessels. Your heart and these blood vessels make up your circulatory system.
At rest, your heart beats at a rate of about 60 to 100 times a minute (a child's heart rate is higher). In an average lifetime, a heart will beat around 3 billion times.
When you are physically active, excited or ill, your heart rate can rise significantly. This is a natural response.
There are two parts to each heartbeat:
Every heartbeat results in blood moving forward through your arteries. You can feel this movement as a 'pulse' by placing two fingers over the artery of your wrist. Your pulse rate tells you how fast your heart is beating.
Some heart problems happen from birth (known as congenital). Others develop over time because of lifestyle and other factors, especially ageing. Some heart problems can be hereditary (passed on through families).
Over time, people can develop conditions like high blood pressure and high cholesterol. These, along with other risk factors, increase your risk of coronary heart disease. Coronary heart disease causes symptoms like angina, and can lead to a heart attack or stroke.
The best way to look after your heart and prevent heart disease is having a heart-healthy lifestyle.