Answer:
Collapsed Lung (Pneumothorax)
Step-by-step explanation:
"A pneumothorax is a collection of free air in the chest outside the lung that causes the lung to collapse.
[...]In some instances, the lung continues to leak air into the chest cavity and results in compression of the chest structures, including vessels that return blood to the heart. This is referred to as a tension pneumothorax and can be fatal if not treated immediately.
Examination of the chest with a stethoscope reveals decreased or absent breath sounds over the affected lung. The diagnosis is confirmed by chest X-ray."
Reference: George Schiffman. “Pneumothorax (Collapsed Lung): Symptoms, Causes & Treatment.” RxList, 2019