Pneumothorax

A pneumothorax, often called a collapsed lung, happens when air escapes into the pleural space, the thin gap between the lung and the chest wall. Normally this space has no air in it, and the slight suction there helps keep the lung expanded. When air leaks in, it pushes on the lung, which can no longer fill properly and partly or fully collapses.

A pneumothorax can range from a small one that causes few symptoms to a large one that makes breathing very difficult. It can affect people with no previous lung problems as well as those with an existing lung condition.

The main symptoms are sudden, sharp chest pain on one side, which may be worse when breathing in or coughing, and shortness of breath. There may also be a dry cough and a fast heartbeat. A small pneumothorax may cause only mild symptoms, while a larger one can cause marked breathlessness.

Seek emergency help straight away for sudden, severe chest pain and breathlessness. A tension pneumothorax is a particular emergency: air keeps building up and presses on the heart and large blood vessels, causing severe breathlessness, a rapid heart rate, and a dangerous drop in blood pressure. This needs immediate treatment to release the trapped air.

A spontaneous pneumothorax happens without an obvious injury, often when a small air-filled blister (bleb) on the surface of the lung bursts. This is more common in tall, thin young people and in people who smoke. A secondary pneumothorax occurs in people who already have a lung condition, such as COPD, asthma, or cystic fibrosis.

A pneumothorax can also be caused by an injury to the chest (a traumatic pneumothorax), such as a broken rib or a stab wound, or, less commonly, as a complication of a medical procedure near the lung, such as a lung biopsy. Changes in air pressure, for example during scuba diving, can also play a role in some people.

A pneumothorax is usually diagnosed with a chest X-ray, which in most cases clearly shows the collapsed lung and the air around it. Doctors will also examine your chest and check your oxygen levels and how hard you are working to breathe.

If more detail is needed, a CT scan can show smaller pockets of air, help measure the size of the pneumothorax, and look for an underlying cause. In an emergency such as a suspected tension pneumothorax, treatment may be started immediately based on the symptoms and examination, without waiting for scans.

Treatment depends on the size of the pneumothorax and how it is affecting you. A small one that causes few symptoms may simply be watched, with rest and sometimes extra oxygen, as the air can be reabsorbed by the body over time. If it is larger or causing significant breathlessness, the air may be removed using a needle (aspiration) or by inserting a small tube called a chest drain to let the air out and allow the lung to re-expand.

A tension pneumothorax is treated as an emergency, with immediate release of the trapped air. If a pneumothorax keeps coming back, or if there is a persistent air leak, surgery may be recommended. This often involves keyhole surgery to repair the leaking area and to help seal the pleural space so it is less likely to happen again.

Most people recover well after a pneumothorax, especially once the lung has re-expanded. However, a spontaneous pneumothorax can return, sometimes on the same or the other side, particularly in people who smoke or who have an underlying lung condition. Stopping smoking is one of the most helpful steps to lower the risk of it happening again.

After a pneumothorax, you may be advised to avoid certain activities for a time, such as flying or scuba diving, until your doctor confirms it is safe. Diving in particular may need to be avoided long-term in some cases. Your care team will give advice based on your situation and recommend follow-up to check the lung has fully recovered.