Respiratory failure is the inability of the lungs to perform gas exchange. It occurs either when the muscles of the ventilatory system fail or when the structures that perform gas exchange are unable to function. People with neuromuscular diseases such as muscular dystrophy and polio may have normal lungs, but they can develop respiratory failure because their disease-weakened muscles are unable to pump air into their lungs.
When gas exchange is impaired, not enough oxygen gets into the blood to fuel the body's metabolic activity. This condition is called hypoxemia. Chronic hypoxemia causes the blood vessels in the lung to contract: the result is pulmonary hypertension. Hypoxemia may also weaken the heart and the circulatory system. Any lung disease, if not adequately treated, can lead to respiratory failure.
Respiratory Acidosis from A.D.A.M.
The Respiratory System from A.D.A.M.