A pleural effusion is an abnormal build-up of fluid in the space around the lungs. This can cause pressure on the lungs, making breathing difficult. It can be a sign of serious illness.
What causes pleural effusion?
If you have a pleural effusion, the fluid has built up between your lungs and the inside of your chest. It sits in and expands a space known as the pleural cavity.
A pleural effusion can be caused by many different conditions, including:
- heart failure
- infections such as pneumonia or tuberculosis
- heart surgery
- kidney failure
- liver or kidney disease
- chest injury
Pleural effusion is different to pulmonary oedema, which occurs when fluid collects in the air sacs in the lungs.
Pleural effusion symptoms
If you have a pleural effusion, you might have:
- difficulty breathing, especially when lying down
- pain in your chest, which may get worse when taking a deep breath
Pleural effusion diagnosis
To diagnose pleural effusion your doctor will examine your chest and may order tests such as:
- blood tests
- ultrasound scan
- computed tomography (CT) scan
- a procedure to remove some of the fluid to be tested
In some cases, your doctor may recommend a thoracoscopy, a surgical procedure which involves examining the pleura and lungs with a special camera inserted into your chest via a thin tube.
Pleural effusion treatment
The treatment depends on the cause of the pleural effusion and how severe it is.
If the pleural effusion is small and not causing any problems, then it might be left alone while the cause, such as heart failure or infection, is treated. Treating the cause will often make the pleural effusion disappear.
If the pleural effusion is making you short of breath, you might have it drained. That can often be done without the need for a stay in hospital.
If the effusion keeps coming back, there are ways to stop it recurring. Talk to your doctor.
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Last reviewed: April 2020