The total number of admissions for heart failure (HF) in the United States is approaching 1 million/year. HF is the number one volume diagnosis in the Medicare health system. Readmission rates are as high as 30 to 60% within 3 to 6 months after discharge even in patients without renal failure, low blood pressure or significant arrhythmias. Patients admitted with HF can be classified into three categories: new-onset HF (5% of total admissions), end-stage or refractory HF (5%), and worsening chronic HF (90%). This review will focus on the epidemiology, prognosis, pathophysiology and pharmacological treatment of patients hospitalized for worsening chronic HF.