This paper reviews the clinical epidemiology of heart failure, emphasizing the need for updated information despite an increase in publications on the topic since 2000. The evaluation and management of heart failure are outlined, covering risk factors, aetiology, prevalence, incidence, prognosis, and prevention. Heart failure is defined as a syndrome with symptoms and signs caused by cardiac dysfunction, leading to reduced longevity. The diagnosis is challenging, especially in primary care, where many patients may have obesity, poor physical condition, pulmonary disease, or ischemia. Heart failure can be acute or chronic, and can be systolic or diastolic, depending on the left ventricular ejection fraction. Asymptomatic left ventricular dysfunction is common and often precedes heart failure. The New York Heart Association (NYHA) classification and the American College of Cardiology/American Heart Association (ACC/AHA) staging system are discussed, highlighting the importance of recognizing high-risk patients and correcting major risk factors. The prevalence of heart failure is estimated at 1-2% in the Western world, with incidence approaching 5-10 per 1000 persons per year. The incidence has not declined over the last two decades, driven by population aging and improved prognosis. Prognosis remains poor, with high mortality rates, particularly within the first few weeks after onset. Determinants of prognosis include patient characteristics, comorbidities, laboratory measurements, functional parameters, and interventions received. Prognostic models, such as the Seattle Heart Failure Model, are useful for stratifying patients. Prevention focuses on managing hypertension and coronary artery disease, with evidence suggesting that treating asymptomatic left ventricular systolic dysfunction can reduce the risk of heart failure.This paper reviews the clinical epidemiology of heart failure, emphasizing the need for updated information despite an increase in publications on the topic since 2000. The evaluation and management of heart failure are outlined, covering risk factors, aetiology, prevalence, incidence, prognosis, and prevention. Heart failure is defined as a syndrome with symptoms and signs caused by cardiac dysfunction, leading to reduced longevity. The diagnosis is challenging, especially in primary care, where many patients may have obesity, poor physical condition, pulmonary disease, or ischemia. Heart failure can be acute or chronic, and can be systolic or diastolic, depending on the left ventricular ejection fraction. Asymptomatic left ventricular dysfunction is common and often precedes heart failure. The New York Heart Association (NYHA) classification and the American College of Cardiology/American Heart Association (ACC/AHA) staging system are discussed, highlighting the importance of recognizing high-risk patients and correcting major risk factors. The prevalence of heart failure is estimated at 1-2% in the Western world, with incidence approaching 5-10 per 1000 persons per year. The incidence has not declined over the last two decades, driven by population aging and improved prognosis. Prognosis remains poor, with high mortality rates, particularly within the first few weeks after onset. Determinants of prognosis include patient characteristics, comorbidities, laboratory measurements, functional parameters, and interventions received. Prognostic models, such as the Seattle Heart Failure Model, are useful for stratifying patients. Prevention focuses on managing hypertension and coronary artery disease, with evidence suggesting that treating asymptomatic left ventricular systolic dysfunction can reduce the risk of heart failure.