A 46-year-old man with no notable medical history presented with a swollen left leg to the ED of a secondary care center. DVT and cellulitis were excluded, and he went home. Several days later, he returned with complaints of dyspnea during exertion, a dry cough, and bilateral lower limb edema. Physical examination showed signs of right-sided congestive heart failure. Subsequent diagnostic assessment excluded pulmonary embolism but demonstrated cephalization of pulmonary vessels, bilateral pleural effusion, hepatic congestion, and elevated N-terminal pro-brain natriuretic peptide levels. Cardiac evaluation demonstrated a normal ECG and no abnormalities on echocardiography, and right-sided heart catheterization was later performed. Meanwhile, the patient had responded well to the initiated loop diuretic with resolution of the dyspnea and pleural effusion. However, the swollen left leg persisted and became painful, which prevented him from going to work. Two months later, the lack of a satisfactory explanation for the clinical picture prompted referral to our tertiary care center.