Reversible pulmonary hypertension with unclear etiology associated with suspected viral infection.

Clinical classification of pulmonary hypertension (PH) includes five groups: pulmonary arterial hypertension (PAH), PH due to left heart disease, PH due to lung diseases and/or hypoxemia, chronic thromboembolic PH, and PH with unclear and/or multifactorial mechanism. PH is categorized according to clinical presentation, pathological findings, hemodynamic significances and treatment strategy. The authors report a case of reversible PH with unknown etiology in association with suspected acute viral illness.