A pleural effusion is a collection of fluid next to the lung. There are various causes. The effusion may cause you to become breathless. The fluid can be drained if necessary. Treatment is mainly aimed at the underlying cause.
A pleural effusion means that there is a build-up of fluid between a lung and the chest wall.
The pleura is a thin membrane that lines the inside of the chest wall and covers the lungs. There is normally a tiny amount of fluid between the two layers of pleura. This acts like lubricating oil between the lungs and the chest wall as they move when you breathe. A pleural effusion develops when this fluid builds up and separates the lung from the chest wall.
A pleural effusion is a complication of various conditions. The following are some of the more common causes of a pleural effusion (but there are other rarer causes too):
You may feel some chest pain but a pleural effusion is often painless. The amount of fluid varies. As the effusion becomes larger, it presses on the lung, which cannot expand fully when you breathe. You may then become breathless.
You may also have symptoms of the condition that is causing the effusion. As a whole range of conditions can cause a pleural effusion, there is a large range of other symptoms that may occur, depending on the underlying cause. One example is you may have a cough and a fever if the cause is lung infection (pneumonia).
A chest X-ray usually confirms a build-up of fluid between a lung and the chest wall (pleural effusion). If the cause of the effusion is known then no further tests may be needed. However, sometimes a pleural effusion is the first sign of an underlying condition. Further tests may then be advised to find the cause of the effusion. These may include lung tests, blood tests, and taking a sample of the fluid and pleura to examine in the laboratory.
A major part of treatment is usually directed to the underlying cause of the build-up of fluid between the lung and the chest wall (pleural effusion). For example, medicines called antibiotics for lung infection (pneumonia), chemotherapy or radiotherapy for cancers, etc. Therefore, treatment can vary greatly, depending on the cause of the effusion. If the underlying cause can be successfully treated then there is a good chance that the pleural effusion will go away for good. If the underlying cause cannot be treated, or can only be partially treated, the effusion may return if it is cleared (drained).
Small effusions that cause no symptoms, or only mild symptoms, may just be left and 'observed'. Treatment is usually only needed if the effusion causes symptoms such as breathlessness.
A large pleural effusion that makes you breathless can be drained. This is called a pleural fluid aspiration or pleural tap. It is usually done by inserting a needle or tube through the chest wall. A local anaesthetic is injected into the skin and chest wall first to make the procedure painless. This may be a 'one-off' procedure to relieve symptoms.
However, in many cases, unless the underlying cause can be treated, an effusion is likely to return within a few weeks. Repeated draining of the fluid, when symptoms become troublesome, is one option.
Depending on the underlying cause, other treatment options that are sometimes considered include: