The build up of fluid presses on the lung making it difficult for the lung to expand fully. As the effusion increases in size difficulties in breathing also increase. In some situations the lung may collpase and this can also increase breathlessness. Breathlness can occur not only when being active but can also occur whilst resting. A pleural effusion is often painless but there may be chest pains. There may also be a cough and a fever which can be a sign of a lung infection (pneumonia).
An effusion does however have to be quite large before it causes any symptoms. If the effusion arises as a result of cancer, it is known as a malignant effusion and can give rise to symptoms other than breathlessness, namely a cough and chest pain.
Causes of an effusion – asbestos exposure
With mesothelioma an effusion is a common symptom that can inhibit the normal function of the lung. In some cases, the presentation of an effusion is a sign that a malignant mesothelioma or lung cancer is developing.
- Lung cancer