What is it used for?A pleural fluid analysis is used to find the cause of pleural effusion. There are two main types of pleural effusion:Transudate, which happens when there is an imbalance of pressure in certain blood vessels. This causes extra fluid to leak into the pleural space. Transudate pleural effusion is most often caused by heart failure or cirrhosis.Exudate, which happens when there is an injury or inflammation of the pleura. This can make excess fluid leak out of certain blood vessels. Exudate pleural effusion has many causes. These include infections such as pneumonia, cancer, kidney disease, and autoimmune diseases. It commonly affects only one side of the chest.To help figure out which type of pleural effusion you have, your health care provider may use a method known as Light's criteria. Light's criteria is a calculation that compares some of the findings of your pleural fluid analysis with the results of one or more protein blood tests.It's important to find out which type of pleural effusion you have, so you can get the right treatment.
