Heart failure is a specific heart condition with many causes, the most common being heart attack, heart disease, heart valve disease, high blood pressure, an irregular heart rhythm, certain infections of the heart, or heart problems you were born with. Heart failure affects over 26 million people worldwide, and is increasing in prevalence. As many as 1 in 5 people over the age of 40 will develop heart failure in their lifetime. It occurs when the heart muscle doesn’t pump blood as well as it should. Heart failure is a chronic and often complex condition which can take years to develop or it can happen quickly at times.