Sputum

Sputum is mucus that is coughed up from the lower airways, such as the trachea and bronchi. It is often called "phlegm." In medicine, doctors look at sputum samples to help understand respiratory infections and study the respiratory system using cytological methods.

Looking at sputum with the naked eye can be useful. For example, if sputum appears yellow or green, it might suggest an airway infection, though it doesn't tell us what kind of germ is causing it. The best way to see these color changes is to place the sputum against a bright white background, like white paper or a sink.

However, not all green, yellow, or thick sputum means there is an infection. Allergies and other factors can also change the color of mucus. So, while sputum color can give clues, it is not a definitive way to diagnose the cause of respiratory issues.

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 because it helps doctors learn about our health.

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 is a sign that the body is fighting an infection. This can happen with illnesses like pneumonia or bronchitis.

Interpretation

When you look at sputum, or phlegm, with your eyes, its color can give clues about what might be happening in the lungs. For example:

• Bloody sputum might suggest irritation in the throat or lungs, or sometimes something more serious like lung disease.
• Green or yellow sputum often points to a long-term infection in the lungs.
• Rust-colored sputum can be linked to certain bacteria or other lung conditions.
• Brownish sputum might show up with chronic lung issues.
• Whitish or milky sputum usually means a viral infection or allergy, not something that needs antibiotics.

Different colors help doctors understand what might be causing breathing problems and decide on the best treatment.