Heart failure (HF) is a major public health issue with a prevalence of over 5.8 million in the USA and over 23 million worldwide. The lifetime risk of developing HF is one in five. Although the age-adjusted incidence of HF may have plateaued, HF still carries substantial morbidity and mortality, with 5-year mortality rivaling that of many cancers. HF represents a significant burden on the healthcare system, costing over $39 billion annually in the USA alone, and is associated with high rates of hospitalizations, readmissions, and outpatient visits. HF is not a single entity but a clinical syndrome with varying characteristics based on age, sex, race, ethnicity, left ventricular ejection fraction (LVEF), and etiology. Pathophysiological differences exist between HF with reduced LVEF and HF with preserved LVEF, which are increasingly recognized in epidemiological studies. Risk factors such as ischemic heart disease, hypertension, smoking, obesity, and diabetes have been identified as predictors of HF incidence and severity. HF prevalence increases with age, affecting more men than women. The worldwide prevalence of HF is increasing, likely due to aging populations, improved treatment of cardiovascular disease, and increased incidence. Incidence of HF has plateaued or may be decreasing in some groups, but overall prevalence is rising. HF and preserved LVEF now account for over 50% of HF cases and can have poor outcomes, though effective management strategies are lacking. HF mortality remains high, with one in eight deaths in the USA having HF mentioned. Mortality risk increases after a new diagnosis, with 5-year mortality ranging from 45-60%. Despite improvements in therapy and management, HF remains a deadly syndrome. In-hospital mortality has improved over time, but it remains high in older populations. Long-term survival has improved, with a 12% improvement per decade after HF onset. HF and preserved LVEF is increasingly recognized, with prevalence rising over time. Risk factors for HF include age, male sex, hypertension, diabetes, and obesity. HF and preserved LVEF is associated with higher risk of mortality and all-cause mortality, even after controlling for age, sex, and LVEF. Risk factors such as hypertension, diabetes, and dyslipidemia contribute to HF development and poor outcomes. HF has a significant impact on healthcare services, with high rates of hospitalizations, readmissions, and outpatient visits. The cost of HF is substantial, with over $39 billion annually in the USA. HF is the most common condition for hospital admission in people over 65 years of age. Hospitalization rates have increased, with a 79% increase in HF hospitalizations as the primary diagnosis between 1979 and 2004. Readmissions are a major burden, with 27% of patients readmitted within 30 days. HF isHeart failure (HF) is a major public health issue with a prevalence of over 5.8 million in the USA and over 23 million worldwide. The lifetime risk of developing HF is one in five. Although the age-adjusted incidence of HF may have plateaued, HF still carries substantial morbidity and mortality, with 5-year mortality rivaling that of many cancers. HF represents a significant burden on the healthcare system, costing over $39 billion annually in the USA alone, and is associated with high rates of hospitalizations, readmissions, and outpatient visits. HF is not a single entity but a clinical syndrome with varying characteristics based on age, sex, race, ethnicity, left ventricular ejection fraction (LVEF), and etiology. Pathophysiological differences exist between HF with reduced LVEF and HF with preserved LVEF, which are increasingly recognized in epidemiological studies. Risk factors such as ischemic heart disease, hypertension, smoking, obesity, and diabetes have been identified as predictors of HF incidence and severity. HF prevalence increases with age, affecting more men than women. The worldwide prevalence of HF is increasing, likely due to aging populations, improved treatment of cardiovascular disease, and increased incidence. Incidence of HF has plateaued or may be decreasing in some groups, but overall prevalence is rising. HF and preserved LVEF now account for over 50% of HF cases and can have poor outcomes, though effective management strategies are lacking. HF mortality remains high, with one in eight deaths in the USA having HF mentioned. Mortality risk increases after a new diagnosis, with 5-year mortality ranging from 45-60%. Despite improvements in therapy and management, HF remains a deadly syndrome. In-hospital mortality has improved over time, but it remains high in older populations. Long-term survival has improved, with a 12% improvement per decade after HF onset. HF and preserved LVEF is increasingly recognized, with prevalence rising over time. Risk factors for HF include age, male sex, hypertension, diabetes, and obesity. HF and preserved LVEF is associated with higher risk of mortality and all-cause mortality, even after controlling for age, sex, and LVEF. Risk factors such as hypertension, diabetes, and dyslipidemia contribute to HF development and poor outcomes. HF has a significant impact on healthcare services, with high rates of hospitalizations, readmissions, and outpatient visits. The cost of HF is substantial, with over $39 billion annually in the USA. HF is the most common condition for hospital admission in people over 65 years of age. Hospitalization rates have increased, with a 79% increase in HF hospitalizations as the primary diagnosis between 1979 and 2004. Readmissions are a major burden, with 27% of patients readmitted within 30 days. HF is