Pneumothorax occurs when the pleura ruptures and gas enters the pleural cavity, often compressing the lung tissue. Patients may experience symptoms such as chest pain, chest tightness, and coughing. The choice of lying position for patients with pneumothorax depends on the severity of the pneumothorax and the degree of chest tightness. If the pneumothorax is mild and the symptoms are not obvious, the patient can lie flat. If there is significant chest tightness, a semi-recumbent position may be adopted. If the chest tightness is severe and the patient has significant difficulty breathing, they often assume a sitting position, frequently struggling to breathe, sweating profusely, and may even experience respiratory failure, requiring immediate attention.