Pleural Fluid Analysis
Reviewed
A pleural fluid analysis is a group of tests on fluid that has built up in the pleural space (between the lungs and chest wall). It helps find the cause of a pleural effusion by determining whether the fluid is transudate (watery, low protein) or exudate (cloudy, high protein). The results guide further testing to identify the underlying condition.
Preparation and collection
In general, no special preparation is needed. Your provider may ask you to stop taking certain medicines (e.g., blood thinners) before the procedure. Always follow your provider's instructions and do not stop any prescription medicine without talking to your provider first.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- A pleural fluid analysis alone may not find the specific condition causing the pleural effusion; it helps narrow down possibilities and guides further testing.
- Results must be interpreted by a healthcare professional in the context of your overall health and other test results.
What to do next
If you have questions about your results, talk with your provider. Treatment for pleural effusion depends on the cause and severity. In some cases, a catheter may be left in place to drain fluid that reaccumulates.