A collapsed lung means air has leaked into the space between your lung and your chest wall, creating pressure that prevents the lung from expanding normally. The medical term is pneumothorax. The main symptoms are sudden, sharp chest pain and shortness of breath, and severity depends on how much of the lung has collapsed. A small collapse may resolve on its own, while a large one requires emergency treatment to remove the trapped air.
How a Lung Collapses
Your lungs sit inside your chest cavity surrounded by a thin, sealed space called the pleural space. Normally this space contains only a tiny amount of fluid that lets your lungs glide smoothly as you breathe. When air gets into that space, either from a hole in the lung itself or from an injury that punctures the chest wall, it disrupts the vacuum-like pressure that keeps your lung inflated. The lung partially or fully deflates, like letting air into the space around a balloon inside a jar.
This can happen spontaneously, especially in tall, thin young men and in smokers, when a small air blister on the lung surface ruptures without any obvious cause. It can also result from chest trauma (broken ribs, stab wounds, car accidents), lung disease like COPD or cystic fibrosis, or as a complication of medical procedures near the chest.
What It Feels Like
The most common symptom is a sudden, sharp pain on one side of your chest or shoulder that gets worse when you take a deep breath or cough. Shortness of breath comes on quickly, and you may feel like you simply can’t get enough air no matter how hard you try.
With a small collapse, these symptoms can be mild enough that some people wait hours or even days before seeking care. A larger collapse causes more dramatic symptoms:
- Bluish skin from lack of oxygen, particularly around the lips and fingertips
- Chest tightness and rapid, shallow breathing
- Rapid heart rate
- Lightheadedness or feeling like you might faint
- Extreme fatigue with minimal effort
In the most dangerous form, called a tension pneumothorax, air continues leaking into the chest space with no way to escape. Pressure builds rapidly, pushing the heart and major blood vessels to the opposite side of the chest. Heart rate climbs above 135 beats per minute, blood pressure drops, and cardiovascular collapse can follow quickly. This is a life-threatening emergency.
How Doctors Diagnose It
A chest X-ray is the standard first step. Doctors look for a visible gap between the lung edge and the chest wall where air has accumulated. They measure the distance at several points on the X-ray to estimate what percentage of the lung has collapsed, which directly determines treatment. In some cases, a CT scan provides a more detailed picture, especially if the X-ray is unclear or the doctor suspects underlying lung disease.
On a physical exam, the affected side of your chest will have noticeably quieter or absent breath sounds when listened to with a stethoscope. Blood pressure may be low, and you may be visibly working harder to breathe on that side.
Treatment Depends on the Size
For a small pneumothorax in someone who is otherwise stable, treatment may simply be observation. Your body can gradually reabsorb the leaked air on its own over days to a couple of weeks, though you’ll be monitored with repeat X-rays to make sure the collapse isn’t getting worse.
For a moderate collapse, doctors may use needle aspiration. A needle and syringe are inserted into the chest to draw out the trapped air directly. This takes about 30 minutes, after which a follow-up X-ray checks whether the lung has re-expanded. If air remains, aspiration is attempted for another 30 minutes. If the lung still hasn’t re-expanded after two rounds, the next step is a chest tube.
A chest tube is a flexible tube inserted between the ribs into the pleural space. It continuously drains air (and sometimes fluid) to let the lung reinflate. You’ll typically have the tube in place for a couple of days or longer, depending on how quickly the air leak seals. This means a hospital stay, though once the tube is working, pain is manageable and you can move around your room.
When Surgery Is Needed
Surgery becomes an option when a collapsed lung keeps recurring or when the air leak won’t seal on its own. The most common approach uses small camera-guided instruments inserted through tiny incisions in the chest wall. The surgeon identifies and removes any blisters or damaged tissue on the lung surface, then performs a procedure to make the lung stick permanently to the chest wall so air can’t accumulate in the pleural space again.
There are two main ways to achieve this. Mechanical pleurodesis involves physically roughening the inner lining of the chest wall until it becomes slightly raw, which triggers the body to form scar tissue that bonds the lung to the wall. Chemical pleurodesis uses an irritating substance, most commonly sterile talc, applied through a chest drain. The talc triggers an intense inflammatory response that creates the same kind of adhesion. Chemical pleurodesis is typically reserved for patients who can’t tolerate surgery due to other health conditions.
Recovery Timeline
Most collapsed lungs heal within a few days to two weeks. If you needed only observation, recovery is mostly about rest and avoiding strenuous activity while your body reabsorbs the air. If you had a chest tube, you’ll stay in the hospital until the tube is removed, then gradually return to normal activity over the following weeks. Surgical recovery is longer but typically measured in weeks rather than months.
Pain during recovery is common, especially with deep breaths and coughing, but it improves steadily. Your doctor will likely schedule follow-up X-rays to confirm full re-expansion.
Recurrence Risk
One of the more surprising aspects of a collapsed lung is how often it happens again. A meta-analysis published in the European Respiratory Journal found that the overall recurrence rate for a first-time spontaneous pneumothorax is about 32%, with roughly 29% recurring within the first year alone. That means nearly one in three people who experience a spontaneous collapse will have another one.
This high recurrence rate is a major reason doctors recommend surgery after a second episode, or sometimes even after the first if the collapse was large or the air leak was slow to seal. The pleurodesis procedures described above dramatically reduce the chance of it happening again.
Flying and Diving After a Collapsed Lung
Air pressure changes at altitude can re-expand any residual air pocket in the chest, so flying too soon is risky. British Thoracic Society guidelines state that you should not fly until at least seven days after a chest X-ray confirms full resolution. If the collapse occurred as a complication of a medical procedure, the same one-week waiting period applies after the X-ray shows the air is gone.
Scuba diving carries an even stricter restriction. The pressure changes underwater are far more extreme than in a plane cabin. A history of spontaneous pneumothorax is considered a permanent contraindication to diving unless you’ve had bilateral surgical pleurodesis and post-surgical imaging confirms normal lung structure and function. A previous traumatic pneumothorax (from an injury rather than spontaneous) may be cleared for diving if it has fully healed and lung function testing is normal, but this requires individual medical evaluation.