The heart beats about 2.5 billion times over the average lifetime, pushing millions of gallons of blood to every part of the body. This steady flow carries with it oxygen, fuel, hormones, other compounds, and a host of essential cells. It also whisks away the waste products of metabolism. When the heart stops, essential functions fail, some almost instantly. Given the heart's never-ending workload, it's a wonder it performs so well, for so long, for so many people. But it can also fail, brought down by a poor diet and lack of exercise, smoking, infection, unlucky genes, and more. So in order to avoid wear down of our heart one should quit smoking, control weight, eat healthily, exercise regularly and get periodic screening for avoiding heart disease.