Aetiology

There are two main types of pulmonary oedema (1)

1. Cardiogenic (hydrostatic) pulmonary oedema

This is due to elevated pulmonary capillary pressure from left-sided heart failure

2. Non-cardiogenic pulmonary oedema

In these cases there is typically minimal elevation of pulmonary capillary pressure (except in cases of volume overload because of renal failure).

In some conditions - such as high-altitude oedema - the mechanism for non-cardiogenic oedema is unclear.

Reference

1. Murray JF. Pulmonary edema: pathophysiology and diagnosis. Int J Tuberc Lung Dis. 2011 Feb;15(2):155-60