Heart failure is a prevalent clinical syndrome affecting over 5 million Americans, often resulting from various cardiac disorders that impair the heart's ability to pump effectively. Key concepts include systolic and diastolic failures, various risk factors, and a range of symptoms such as dyspnea and fatigue, which may lead to significant complications like pulmonary edema and atrial fibrillation. The management of heart failure includes lifestyle changes, pharmacological interventions, and the use of diagnostic tests to determine underlying causes.