According to the British Heart Foundation, There are around 7.6 million people living with a heart or circulatory disease in the UK: 4 million men and 3.6 million women.
Cardiovascular surgeon Dr Jeremy London said in a video that these are three red flags you should never ignore:
Shortness of breath while walking
While we may laugh it off and put it down to being simply unfit, Dr Strong warned that this is a sign of a weak heart.
The NHS states that while shortness of breath may not be serious, "Do not try to self-diagnose the cause of shortness of breath - always see a GP."
According to The Sleep Foundation, this is caused by something called Orthopnea, whcih is a shortness of breath some people experience when lying down, which goes away once they return to an upright position.
While there can be many reasons for swollen legs and ankles, if the symptoms don't go away, it could be due to heart failure.
The NHS recommends that you should see a GP if one or both of your ankles, foot or legs are swollen and:
Dr London added: "In my world of cardiac surgery, heart function is the single most determiner of how patients do with surgery.
"Patients with strong hearts do much better than patients with weak hearts."
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