Color vision is an amazing thing. All the colors we perceive are present in normal sunlight. If you shine normal sunlight through a triangular piece of glass, called a prism, you can see all the components present in the light. Color affects different people in different ways.  We all usually have a favorite color or use a specific color more at different times or occasions. The science behind our emotional response to color is a complex one. Some of our responses to color may be hard wired in our brain.  Red seems to be a color of stimulation and excitement, while blue is more relaxing and calming.  Similar traits can be ascribed to yellow and green.

What does this all have to do with lung problems? One of the misconceptions I often need to address with patients is the color of their mucous when they cough.  Most patients feel that if the mucous is green or yellow it must be infected.  This often leads to repeated courses of antibiotics which, in most cases, is unnecessary.

Here is what you need to understand.  The color of your mucous is primarily dependent on the length of time it has been sitting in your tracheobronchial tree.  Most patients will relate that the morning sputum is discolored compared to later  in the day. The truth is, sputum can be highly infected and be white, or almost clear. My advice would be not to take repeated courses of antibiotics just because of color.