Pulmonary congestion occurs when the amount of extravascular fluid in the lungs increases. Pulmonary congestion develops in 2 stages.

pulmonary congestion x-ray

Interstitial edema occurs with collection of fluid in the interalveolar septa and Kerley B lines appear. Kerley B lines are seen as 3-6 mm long horizontal lines in the lateral basal segments of the lung, near the chest wall (on the frontal film). They develop when the pressure in the interstitium exceeds about 18-20 mm Hg. At this stage, the patient usually becomes dyspnoeic with tachypnoea, but with minimal changes in the arterial blood gases.

Pulmonary congestion is the cause of death of the 38-year-old former child star, Judy Haim — who has spent his last year striving against breast cancer.