Curious about your snot? Plenty of people take a peek at what winds up in their tissue after a good nose blow, but doctors say this curiosity can actually give you clues about your health.
"Increased mucus production can be a sign of multiple things," allergist and immunologist Dr. Tania Elliott, chief medical officer at Nectar Allergy, tells Yahoo Life. "Is it allergies? Is it an infection? Is it something to do with your indoor air quality? Understanding your triggers is the key to making your symptoms better."
But what is mucus, exactly, and what can it tell you? Allergists break it down.
What is mucus?
Mucus is a substance that covers the moist surfaces of your body, like your eyes, nostrils, lungs and gastrointestinal tract, according to the National Institutes of Health (NIH). Mucus has trillions of microbes and is a first line of defense against microorganisms that cause infections, the NIH says.
"Mucus is very helpful in terms of our immune system," Elliott says. "When you have a foreign particle like pollen or a virus or bacteria, your mucosal cells — which produce mucus — are stimulated." Then mucus can help carry pathogens out of your body, whether you blow your nose or cough it up, she says.
How to decode your mucus
The color of your mucus can tell you information about your health. These are the main colors you're likely to see and what each means:
Thin and clear. This is very common with allergies, Dr. Purvi Parikh, a board-certified allergist and immunologist with the Allergy and Asthma Network, tells Yahoo Life.
Bright yellow or dark green. This is usually a sign of an infection, Parikh says. "People assume that this means they have a bacterial infection, but this isn't always the case," she says. "You can have bright yellow, dark green mucus, even with viruses."
Pink or red. This typically means there's blood in your mucus, Elliott says, "usually because the nasal passages are too dry and there is scabbing in there."
Brown or black. This could be a sign of a fungal infection, Parikh says. "Believe it or not, it can even be caused by air pollution," she says.
When to see your doctor
If you have an infection, it's important to see a doctor to get properly diagnosed and treated. Parikh and Elliott say these are signs to keep on your radar:
Your mucus abruptly changes color
Your mucus suddenly has a smell to it
Your mucus leaves an unusual taste in your mouth, like a metallic taste
You have a fever
You feel run-down
You have nausea
You have diarrhea
How to manage your mucus
"You don't have to suffer from mucus and phlegm production all fall and winter long," Elliott says. "There are things you can do to help cure you of your allergies, irrigate your nasal passages and get those symptoms under control."
Parikh recommends breathing in steam. "The steam itself can help open up your nasal passages and break up some of that mucus," she says. Thick mucus can be a sign that you're dehydrated, so making sure to drink plenty of water can be helpful, she says.
In a perfect world, Elliott says, you'll keep your mucus flowing. "You don't want your mucus to be stagnant because when it is and it's not flowing, foreign particles, viruses [and] bacteria can all build up," she says.
But if you're dealing with more mucus than usual or you suspect that you may have an infection, Elliott says it's time to see your doctor. "Getting evaluated and understanding what you're dealing with and what's triggering that mucus production is the most important thing that you can do," she says.