A 29 yr old unmarried female presents with dyspnea. Her chest X-ray is normal, FVC is 92%, FEV1/ FVC is 89% and DLCO is 59% of normal. On exercise her oxygen saturation drops from 92% to 86%. What is the likely diagnosis ?
High-Yield Explanation
In primary pulmonary hypeension: Pulmonary function tests shows Non restrictive Non obstructive FVC,FEV1,FEV1/FVC Are normal where as DLCO is characteristically decreased