There are certain myths connected to different colors of mucus, however, there isn’t always scientific data to support them. Below is a list of the different colors phlegm can appear as, the myths associated with them, and ultimately, what snot says about your health:
Clear
When your mucus is clear, it means you are healthy. In order to keep your mucus healthy, you need to stay hydrated. Drink plenty of fluids to keep your mouth and throat moist. To keep your nose hydrated, rinse your nose with salt water, but not too often since it might have the opposite effect. It is also important to keep the air in your living and working space humid, especially in the winter.
White/gray color
There are certain misconceptions that drinking milk and other dairy products leads to white or gray color of mucus, but there is no scientific data to support this claim.[2] However, it causes the mucus to thicken, thus making it harder for you to expel it. When your mucus is white or gray, it means that it is coming from your sinuses, which normally doesn’t happen. However, when there is an inflammation, it can cause mucus to drain to throat, as Dr. Steve Okhravi, an emergency physician suggests[3].
Yellow/green color
Having yellow or green mucus is not always a reason to panic and immediately call your doctor. It may be the sign of an infection, since when an infection occurs, the immune system sends white blood cells which contain a green protein that can color the mucus. However, according to one study[4], it was discovered that yellow or green color is not always a sign there is an infection in our body, since only 46% of the samples collected were culture-positive. In some cases, the yellow or green color of mucus can be a result of seasonal allergies and has nothing to do with viral or bacterial infections.
Dark yellow/brown color
There are several possible reasons for the brown color of mucus[5]. If you are a smoker, the mucus your body produces can have a tendency to be a brown color because of various matters in cigarettes. If you are not a smoker, the brown color of your mucus can be the result of certain types of food you ate or beverages you consumed, such as chocolate, coffee, or red wine. However, if accompanied by other symptoms, such as a fever for example, you should seek medical advice.
Pink/red color
When mucus is a pink color that means there is a little blood in it. For example, blood can come from blood vessels in your nose. However, a pink/red color may also indicate certain severe conditions[6], such as pulmonary edema (fluid in lungs), tuberculosis, pneumonia, pulmonary embolism, and cancer. So, if there is an excessive amount of blood in your mucus and it doesn’t stop, seek medical help.
Black color
Black mucus might mean you inhaled dirt, dust, or smoke, or might be the influence of certain environmental factors. It might also signal there is a chronic sinus infection or fungus, as Scott Stringer, MD, Professor of Otolaryngology at the University of Mississippi Medical Center suggests. In order to prevent the mucus from building up and causing complications, you need to stay hydrated by drinking at least 8 glasses of water and hot liquids a day, and avoid consuming dairy products. In order to loosen mucus, the better choice would be spicy food, which is known to clear the nasal passages. Also, try to blow your nose as often as possible, inhale steam from boiling water, gargle your throat with warm water and salt, and stay away from smoke.
