How the heart works and how to keep it healthy for longer – doctors explain
- For an organ the size of two clenched fists, your heart does an amazing job. You need to keep it healthy for it to keep on pumping without having a problem
- Doctors run through the basics of heart health, and the medical advances that have made it much easier for them to keep our hearts beating properly for longer
The human heart is the most incredible pump. A plumber’s dream, it keeps going for years without leaking, draining, needing valve replacements or breaking down and stopping – if we look after it well.
A kitchen tap would need to be turned on full blast for more than 45 years for the amount of water released to equal the amount of blood the heart pumps in an average lifetime: it pumps 60ml (2 fluid ounces) of blood at every beat, 7.6 litres (2 gallons) each minute, and more than 7,500 litres (2,000 gallons) every day.
How hard does the heart work at each beat? Pick up a tennis ball and squeeze it; that’s how hard a beating heart has to work to pump blood around the body. The veins and arteries that thread their way around the cardiovascular system would, if stretched out, cover a distance of 97,000km (60,000 miles). That’s a lot of piping.
It’s not even that big, about the same size as two clenched fists pressed together, in adults, and weighs just 200-250 grams (7-9 ounces).
Dr Vincent Tsang Chi-yan at the Hong Kong Asia Heart Centre in Hong Kong’s Mong Kok neighbourhood, says: “The heart grows as the body grows; its size becomes static at the age of around 20.”
The heart starts to beat in a woman’s uterus when a fetus is four weeks old. A newborn baby has about a cup of blood in their circulation and their hearts beat about twice as fast as that of a healthy adult: 150 times a minute compared to 75.