Top 10 Trends in Medicine, July 2014

July 28, 2014

#6 Clinical Trend: Light's Criteria

Light's criteria differentiate pleural fluid transudates from exudates in patients with suspected pleural effusion. The fluid is considered an exudate if the ratio of effusion protein to serum protein is greater than 0.5; if the ratio of effusion lactate dehydrogenase (LDH) to serum LDH is greater than 0.6; or if the effusion LDH level is greater than two thirds the upper limit of the lab's reference range for serum LDH.

Detailed Clinical Information:

Light's Criteria

Did you know:

In patients with pleural effusion, Light’s criteria will determine whether the effusion is an exudate. Light’s criteria have a 98% sensitivity and 83% specificity for identifying exudative effusions.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.