If Flash Pulmonary Edema was referred to as Circulatory Insufficiency that would be correct. This condition only occurs is people with cardiovascular disease and the origin of it is dysfunction of the cardiovascular system. It is not primarily a pulmonary disease. This misunderstanding has been made worse in recent years by the introduction of non-invasive ventilation. The image of a patient severely short of breath with a mask connected to a ventilator paints a picture that is misleading. Everyone in the room where this treatment is employed gets the wrong impression. This is not a respiratory or pulmonary illness as it appears in this situation. The cause of this illness despite the fact that edema of the lungs is a part of it is insufficiency of the cardiovascular system. If we removed the edema of the lungs we would still have the inadequate flow, the body would still be starved of the flow of blood and oxygen and there would still be the feeling of shortness of breath. The body feels a lack of oxygen at the tissue level even if the oxygen of the arterial blood is normal or near normal. Edema of the lungs is the result of the problem not the proximate cause.