The clinical symptoms of respiratory failure mainly manifest as hypoxemia and carbon dioxide retention. Looking at their clinical manifestations, mild hypoxia may not show any clinical symptoms. As the severity of the disease increases, there can be signs of increased respiratory drive, such as rapid breathing or difficulty breathing, along with symptoms of sympathetic nervous system activation, such as anxiety and sweating. Hypoxemia can cause dilation of peripheral arteries and constriction of veins, leading to an increased heart rate, or even severe arrhythmias. Furthermore, considering the clinical manifestations of carbon dioxide retention, they are directly related to the levels of carbon dioxide in the body, mainly depending on the rate of occurrence. Clinically, this primarily affects myocardial contractility, the contractile ability of respiratory muscles, and increases in intracranial blood flow. In mild to moderate cases, it can stimulate the respiratory center causing increased and shallow breathing, but in severe cases, it may suppress the respiratory center.