In ARDS there is respiratory failure (the lungs stop functioning normally and mechanical ventilation is needed) with a sudden onset due to the rapid accumulation of fluid or toxins in the lungs and body. This follows an abrupt increase in the fluid and plasma moving out of the blood stream and into the air sacs interfering with the exchange of oxygen. ARDS is the most serious response to acute injury and the causes are very diverse. They include but are by no means limited to; aspiration (getting food or fluids down the wrong way), inhalation of a toxic substance such as smoke from a fire, widespread infection and near-drowning,