1) Acute pulmonary edema is caused by fluid accumulation in the lungs due to increased pulmonary capillary pressure from conditions like heart failure.
2) It can be diagnosed based on symptoms of shortness of breath, chest imaging showing fluid in the lungs, and high BNP levels.
3) Initial treatment focuses on oxygen, diuretics to reduce fluid overload, vasodilators to reduce afterload, and in some cases non-invasive ventilation to help with breathing.