Symptoms of a collapsed lung vary. They may include:
- Falling oxygen levels in the blood, which causes the person to look bluish or ashen and can bring on abnormal heart rhythms (arrhythmias)
- Fever if an infection is present
- Rapid, shallow breathing
- Sharp pain on the affected side, if the symptoms are severe and the blockage occurred quickly
- Shock with a severe drop in blood pressure and a rapid heart rate
- Shortness of breath, which can be sudden and extreme in severe cases
If the blockages happen slowly, there may be few or no symptoms. Those that do occur may include shortness of breath, an increased heart rate or a hacking cough that does not seem to go away.
Causes and Risk Factors
A collapsed lung is often the result of pressure on an airway from outside - a swollen lymph node or fluid between the lining of the lungs and the chest wall, for example - can also cause a lung to collapse.
When the airway is blocked, the blood absorbs the air inside the air sacs (alveoli). Without more air, the sac shrinks. The space where the lung was before the collapse fills up with blood cells, fluids and mucus. It may then become infected.
Other factors can lead to a collapsed lung include:
- A plug of mucus, a tumor or something breathed into the lungs.
- Abdominal swelling
- Experiencing high speeds, such as being a fighter jet pilot
- Injuries, such as from a car accident, a fall or a stabbing
- Lack of the liquid (surfactant) that coats the lining of the alveoli, which helps keep it from collapsing. This can happen in premature babies or in adults who have had too much oxygen therapy or mechanical ventilation.
- Large doses of opioids or sedatives
- Lying immobilized in bed
- Scarring and shrinking of the membranes that cover the lungs and line the inside of the chest, which can occur as a result of exposure to asbestos
- Surgery, especially involving the chest or abdomen
- Tight bandages