A 65-year-old female presented with breathlessness, swelling of the face and legs, and decreased urine output. Examination revealed elevated jugular venous pressure, bilateral pitting edema, and crepitations in both lung bases. Investigations showed hypothyroidism. She was diagnosed with heart failure due to acute left ventricular failure and hypothyroidism. Thyroxine replacement therapy and diuretics were started, and her symptoms improved.