Sputum

Sputum is mucus that you cough up from your lower airways, like the trachea and bronchi. It is often called "phlegm." Doctors look at sputum samples to learn about infections in the lungs and to study the respiratory system using cytological methods.

Looking at sputum with your eyes can sometimes be helpful. For example, if sputum looks yellow or green, it might mean there is an infection in the airways, but it doesn’t tell us what kind of germ is causing it. The best way to see these color changes is to put the sputum on a bright white background, like white paper or a sink.

Not all green, yellow, or thick sputum means there is an infection. Things like allergies can also change the color of mucus. So, while sputum color can give some clues, it is not a sure way to know the cause of respiratory problems.

Description

Sputum is a kind of mucus that comes from deep in our lungs when we cough. It is different from the spit in our mouths. Doctors look at sputum in the lab to check for germs that might make us sick, like certain types of bacteria. If sputum looks yellow or green, it may contain pus, which can mean the body is fighting an infection. This can happen with illnesses like pneumonia or bronchitis.

Interpretation

When you look at sputum, or phlegm, its color can help doctors understand what might be happening in the lungs. Here are some examples:

• Bloody sputum might suggest irritation in the throat or lungs.
• Green or yellow sputum often points to a long-term infection in the lungs.
• Rust-colored sputum can be linked to certain bacteria or lung conditions.
• Brownish sputum might show up with chronic lung issues.
• Whitish or milky sputum usually means a viral infection or allergy.

Different colors help doctors decide on the best treatment for breathing problems.