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
• kidney failure
• liver disease
• low blood protein levels
• blockage of a major blood vessel
• cancer
• 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
• cough
• fever
• pain in your chest

Pleural effusion diagnosis

To diagnose pleural effusion your doctor will examine your chest and may order tests such as:

• blood tests
• X-rays
• ultrasound scan
• computed tomography (CT) scan

You might need to have some fluid removed from your lungs with a thin needle so it can 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 its severity.

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.