Life threatening unilateral pulmonary oedema at moderate altitude.

A-23-year-old medical student, resident of an altitude of 700 meters, developed dyspnea and cough during a temple visit at an altitude of 2200 m within 10 hours of arrival and his symptoms improved on descending and with 100% oxygen. Chest skiagram and CT scan chest revealed soft fluffy shadows on the left side with small right lung and absent right pulmonary artery. Absent right pulmonary artery was responsible for development of pulmonary oedema at moderate altitude.