What Does the Color of the Fluid Drained From Lungs Mean?

By Staff WriterLast Updated Mar 26, 2020 1:04:44 AM ET

Healthy fluid drained from the lungs during a thoracentesis is light yellow in color and clear, notes Lab Tests Online. Red fluid contains red blood cells. Cloudy fluid is indicative of high protein levels and may be a sign of contamination with white blood cells or microorganisms.