Allergies can cause white phlegm (mucus) or phlegm that has no color. Allergy treatment can include taking an antihistamine, using a nasal steroid, or consulting with an allergy specialist.

What Does the Color of Phlegm Mean? While diagnosing the cause ... Infection is a common cause, but other conditions like allergies, lung disease, and GERD can cause a productive cough.

A runny or stuffy nose can be a symptom of the flu, a cold or allergies, and it can be hard to discern which one you have. So how do you know what’s really going on with your nose? “More than likely ...

The color of mucus doesn't reveal whether it's a viral or bacterial infection. The cause of congestion could instead be an allergy, which would require a doctor visit and possibly an allergy test.