What is respiratory failure? Respiratory failure is the inability of the respiratory system to adequately supply fresh oxygen or remove carbon dioxide, resulting in low blood oxygen or high blood carbon dioxide levels, respectively. Multiple conditions can cause one or both of these problems. Acute or sudden respiratory failure can happen as the result of trauma, injury, drug or alcohol overdose, or inhalation of carbon monoxide. Chronic, or long-term, respiratory failure is commonly caused by chronic obstructive pulmonary disease (COPD), neuromuscular disease, or even morbid obesity. The signs and symptoms of respiratory failure differ depending on the severity and underlying cause. Acute respiratory failure occurs rapidly and can resolve with treatment. Chronic respiratory failure, on the other hand, is a progressive disease, which typically worsens over time. Symptoms of respiratory failure include difficulty breathing, cyanosis (blue or purple coloration of the skin), and lethargy. Treatment depends on the severity of the disease and may include oxygen support, bronchodilators, and ventilatory support. Respiratory failure can be a serious or life-threatening condition. Seek immediate medical care (call 911) if you, or someone you are with, have serious symptoms, such as severe difficulty breathing; severe sharp chest pain; bluish coloration of the lips or fingernails; a change in level of consciousness or alertness, such as passing out or unresponsiveness; and rapid heart rate. Seek prompt medical care if you are being treated for respiratory failure but mild symptoms recur or are persistent.