A young lady with dyspnoea: Quest for the cause.

Pulmonary hypertension (PH) is a common cause of dyspnoea. The management and prognosis of PH varies with the underlying aetiology. Hence the detection of the cause of PH is important. Obliterative bronchiolitis (OB) is a common but under-recognised cause of PH. OB is usually secondary to childhood infections known as post-infectious OB. It can also be secondary to other diseases, but cryptogenic OB is an extremely rare entity. Here we share a unique case of PH due to cryptogenic OB and its successful outcome with optimal management.