Respiratory failure and lethargy should be treated immediately. Respiratory failure is a dysfunction of ventilation or/and gas exchange in the lungs caused by various reasons, resulting in lack of oxygen to the body. Lesions of the trachea, lung tissue, pulmonary blood vessels, and the nervous system can lead to respiratory failure, which is categorized as Type I respiratory failure and Type II respiratory failure, with common symptoms such as dyspnea and dysphoria. Drowsiness is a kind of consciousness disorder, strong stimulation can only wake up the patient, respiratory failure because of the lack of oxygen, sometimes accompanied by carbon dioxide retention, easy to cause lethargy or other mental state abnormalities. However, other neurological pathologies should be ruled out by a medical professional before drowsiness caused by respiratory failure can be suspected. Whether it is respiratory failure, lethargy, or respiratory failure accompanied by lethargy, it is important to seek immediate medical attention to prevent delays in the best time to save the patient’s life.