How the Heart Works
Your heart generally beats without conscious effort. It started before you were born and will continue for as long as you live, pumping blood to every part of your body around the clock.
At rest, the average adult heart beats around 72 times per minute. That works out to about 100,000 beats every day, or around 36 million beats over the course of a year. Someone who lives to 80 will have a heart that has beaten approximately three billion times, though this varies considerably depending on fitness level, age and health conditions throughout life.
Each beat pushes blood out of the left ventricle and into the circulatory system. This blood has just passed through the lungs, where it picked up a fresh supply of oxygen. The arteries then carry it to every organ, tissue and cell in the body.
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With each contraction, the heart ejects roughly 70 millilitres of blood. This may not sound like much, but it adds up quickly.
Over a single day, your heart pumps around 7,000 to 8,000 litres of blood, depending on your activity level and individual physiology. Across a year, that figure rises to about 2.5 million litres. Over an 80 year lifespan, the total reaches somewhere in the region of 200 million litres. That would fill roughly 80 Olympic swimming pools.
The blood leaving your heart travels at speed. In the aorta, the main artery leading away from the heart, blood moves at approximately 300 to 500 millimetres per second, varying between individuals. As it passes into smaller arteries and then into the tiny capillaries that supply individual cells, the flow slows considerably. This slower pace allows oxygen and nutrients to pass into tissues and waste products to be collected for removal.
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A Muscle That Never Rests
Even when you are sitting still, your heart is working steadily. Unlike other muscles in the body, the heart cannot take a break. It beats continuously, adjusting its rate and force according to what your body needs at any given moment.
During exercise, the heart beats faster and pumps more blood with each contraction to meet increased demand for oxygen. During sleep, the rate typically drops as the body's requirements decrease. This constant adjustment happens automatically, controlled by electrical signals within the heart itself and by the nervous system. External factors such as stress, caffeine and medication can also influence heart rate.
The heart muscle receives its own blood supply through the coronary arteries. These relatively small vessels wrap around the outside of the heart and deliver the oxygen and nutrients the muscle needs to keep functioning. When these arteries become narrowed or blocked, it can lead to problems such as angina or heart attacks.
Looking After Your Heart
Given how hard the heart works throughout life, keeping it healthy is worth the effort. The British Heart Foundation recommends regular physical activity, a balanced diet, maintaining a healthy weight, not smoking, and limiting alcohol intake. These measures can reduce the risk of heart disease and help the heart function well for longer.
If you have concerns about your heart health, your GP is a good starting point. They can arrange tests, provide advice, and refer you to a cardiologist if needed. The NHS website also offers reliable information on heart conditions, symptoms to watch for, and when to seek medical help. Both the NHS and British Heart Foundation regularly review and update their content according to the latest clinical guidelines.
For specific guidance on heart conditions or treatment options, the British Heart Foundation and NHS websites offer detailed, current information tailored to UK readers.
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