What Does Green Snot Tell You About Your Health?

The mucus on your tissue matters more than you think.

Your nose feels a little runny or sniffly. You reach for the Kleenex—and when you blow into it, you notice that the snot on the tissue is green. 

Hmm, that's weird, you think. Usually, it's white or maybe a little yellow, so what does it mean that you now see green? 

Here's what you need to know about why green snot happens, what it may indicate about your health, and what you should do about it.

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What Does Green Snot Mean?

Green, or yellow-green, mucus is one of the telltale signs that your body is working hard to fight an infection. Typically, if your symptoms (such as fever, sore throat, or cough) are mild, infections aren't worrisome. And if you see green snot on your tissue, that means your body is working as it should to flush those infectious bugs out of your system.

Different types of infections that may cause green mucus include:

  • Viral: Infections caused by viruses, such as COVID-19, the flu, or the common cold.
  • Bacterial: Infections caused by bacteria, such as sinus and ear infections (both of which may also be viral infections).

"Green snot typically means that your immune system is trying to fight off an infectious agent," Cory Fisher, DO, a family medicine specialist based in Rocky River, Ohio, told Health. That infectious agent is probably a virus, but it could be bacteria.

What exactly causes nasal mucus to change to a gross color? Pin the blame on your body's chemicals that fight those infectious bugs. 

"White blood cells called neutrophils are the body's way of fighting infection," Philip Chen, MD, an associate professor of otolaryngology and rhinology at the University of Texas Health Science Center at San Antonio, told Health. "These cells release chemicals to fight infection, and they can be colored, resulting in colored mucus."

After white blood cells fight the infection, your body gets rid of them along with the infection-causing bacteria or viruses. The yellow color comes from dead white blood cells, which can turn green if there are a lot of white blood cells and other debris, per Dr. Chen.

What Color Should Snot Be?

Generally, snot is clear, said Dr. Chen, "but some mild coloration is not typically cause for alarm." Basically, the color of your nasal mucus alone doesn't clue you into anything specific about your health.

Still, some colors are more associated with specific conditions or environmental factors than others, such as:

  • Brown: Dried blood or inhaling something brown, such as dirt or cigarette smoke, can cause brown mucus. It's typically normal and not worrisome. "Brownish mucus can also occur when [the] air is dry and small amounts of blood are in the mucus," added Dr. Chen.
  • Black: Additionally, black mucus can be a result of inhaling something dark, such as cigarette smoke or dust. It may also be a symptom of a fungal infection.
  • Red or pink: If your mucus is red or pink, blood is the primary reason. It might be the result of an injury to your nose or too much friction from too much blowing or rubbing of your nose. The color may be a result of something as simple as dryness in the air.

Does Snot Turn a Different Color When You Have a Cold or Other Infection?

It can, but not always. 

"Sometimes there will be a white tint," said Dr. Chen. "At times, it can be yellow, green, or sometimes a mix of these colors. None of these are tell-tale as to what kind of infection you have."

If a virus gets into the sinuses, your nose may start making extra mucus to clear the virus. After a few days, the mucus might turn white as it gathers up the enemy cells and escorts them out of your body.

While the color might not change if you've caught a cold or flu, other characteristics of your snot might. 

"Oftentimes with a common cold, the mucus is clear—no color or tint—but is typically stickier and thicker than usual," added Dr. Chen.

A Quick Review

Patients concerned about the color of their snot are typically also worried about other symptoms. If it's just green snot you're seeing, but you otherwise feel fine, you likely don't need medical attention.

But if your nasal mucus looks green, your nose is stuffed up or runny, and you have head or body aches and feel feverish, you may assume you're coming down with something. If some accompanying symptoms are serious enough, check in with a healthcare professional.

Also, keep in mind: Green mucus is not necessarily a sign of COVID-19, but it could possibly indicate infection if accompanied by other COVID-19 symptoms.

The most common symptoms of COVID-19 include sore throat, cough, and shortness of breath. But a runny nose or congestion can be, as well. So, if you're blowing your nose a lot, have other COVID-19 symptoms, or were recently exposed to the virus, consider receiving a COVID-19 test to make sure.

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Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Know the signs and symptoms of infection.

  2. National Library of Medicine. Viral infections.

  3. Penn Medicine. A look at what your mucus says about your health.

  4. NIH News in Health. Marvels of mucus and phlegm.

  5. National Library of Medicine. Coughing up blood.

  6. New York City Department of Health and Mental Hygiene. COVID-19: When you are sick.

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