Sudden-onset collapsed lung (spontaneous pneumothorax)

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What is a collapsed lung?

A sudden-onset collapsed lung is medically known as a spontaneous pneumothorax. It occurs when air becomes trapped between the lungs and chest wall, causing the lungs to collapse -- partially or completely.

The condition is called ‘spontaneous’ because it develops without an obvious external cause, such as chest trauma.

There are two types of spontaneous pneumothorax: primary and secondary. A primary spontaneous pneumothorax occurs in people with no known chest conditions, while secondary spontaneous pneumothorax happens in people with existing chest disease.

A sudden-onset collapsed lung can be life-threatening and needs prompt treatment. See your doctor or go to a hospital if you have, or think you may have, a spontaneous pneumothorax.

What are the symptoms of a collapsed lung?

Chest pain is a common symptom of spontaneous pneumothorax. This pain usually develops suddenly and is often:

  • sharp and stabbing in nature
  • on one side of the chest
  • worse on breathing in

Difficulty breathing or shortness of breath
that comes on suddenly is another common symptom of spontaneous pneumothorax.

However, if you have a small pneumothorax, you may not have any symptoms at all.

What are the causes of a collapsed lung?

There are two types of spontaneous pneumothorax: primary and secondary spontaneous pneumothorax.

Primary spontaneous pneumothorax

A primary spontaneous pneumothorax is the most common type of sudden-onset collapsed lung. It is most commonly seen in tall, thin young men.

The condition happens without an obvious cause (such as a chest injury) and in people without existing lung disease.

A primary spontaneous pneumothorax is thought to develop when small sacs of lung tissue, called blebs or bullae, burst without warning. Blebs and bullae tend to lie along the edges of the lungs and may be inherited or caused by smoking.

Secondary spontaneous pneumothorax

Secondary spontaneous pneumothorax is a complication of lung diseases, such as

chronic obstructive pulmonary disease
lung cancer
and some lung infections.

The condition is thought to occur because existing lung disease can weaken the lung tissue, especially where bullae have developed. Weakened lung tissue is more likely to tear and allow air to escape from the lung, causing a pneumothorax.

How is a collapsed lung diagnosed?

Spontaneous pneumothorax can be a life-threatening condition. Go to a hospital immediately if you suddenly develop chest pain and/or shortness of breath.

Your doctor may diagnose a sudden-onset collapsed lung based on your symptoms, medical history and an examination of your chest.

You will usually be given a chest X-ray to confirm the diagnosis.

What is the treatment for a collapsed lung?

Spontaneous pneumothorax treatment usually depends on your symptoms and the size of the pneumothorax.

If you have a small lung collapse, you may not need any treatment. This is because the tear that caused the air leak often heals on its own within a few days. Any trapped air is gradually absorbed into the body.

However, a large spontaneous pneumothorax needs treatment to remove the trapped air. Several procedures can be used to do so, including:

  • putting a needle through your ribs and sucking out the air using a syringe (needle aspiration)
  • making a small hole between your ribs and inserting a thin tube (chest drain) through the hole to remove the air - the tube may be left in place for a few days
  • surgery to close the air leak if a needle aspiration or chest drain does not work

Can a collapsed lung happen again?

A spontaneous pneumothorax can recur, often in the same lung as before.

If this happens, your doctor may recommend a surgical procedure to help prevent another lung collapse in the future.

This procedure may involve repairing the weak part of your lung underlying the air leak. Your doctor may also put a type of powder onto the surface of your lung. This can help the lung to stick to your chest wall, preventing air from leaking into the space between the lung surface and chest wall.

If you are a smoker, you can reduce your risk of another pneumothorax by

quitting smoking
. Changes in environmental pressure, such as being at high altitudes or diving underwater, can also increase your risk of another pneumothorax.

If you have had a spontaneous pneumothorax, speak with your doctor before scuba diving or flying in a plane. They will be able to advise you about if or when it will be safe for you to resume those activities.

What is the outlook after a lung collapse?

Spontaneous pneumothorax is a potentially serious, but treatable, condition. However, it can cause complications, including a life-threatening type of pneumothorax called a tension pneumothorax.

A tension pneumothorax is particularly dangerous because when it happens, air continues to gather between the lung surface and the chest wall with every breath you take. This puts pressure on the lungs and heart, which needs to be relieved urgently.

If you have a spontaneous pneumothorax, or suspect you do, go to a hospital immediately.

Date of last review: 16 June 2020


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Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.