What Green Mucus Means

Green mucus may mean a bacterial or, less often, viral infection, but that's not always true. You constantly breathe in bacteria, some of which are harmless, through your nasal passages. A build-up of bacteria may cause green mucus without making you sick.

You may wonder whether you need antibiotics if you blow your nose and notice your snot is green. Antibiotics only treat bacterial infections, but your mucus color alone cannot tell whether an infection is bacterial or viral.

You may not need antibiotics, even with a mild bacterial infection. Still, consult a healthcare provider if your symptoms do not improve or worsen.

Read on to find out why green snot happens and what it may indicate about your health.

What Does Green Snot Mean?

Green, or yellowish-green, mucus is one of the telltale signs that your body is working to flush germs that cause infections out of your system, Cory Fisher, DO, a family medicine specialist based in Rocky River, Ohio, told Health.

That infectious agent may be bacteria, like those that cause sinus infections. Viruses may cause sinus infections, though they typically cause clear or, less often, light yellow mucus.

Other viruses that may cause yellowish-green mucus include:

• Coronaviruses, like SARS-CoV-2, which causes COVID-19
• Flu viruses
• Rhinoviruses, which are responsible for most cases of the common cold

What Causes Nasal Mucus To Change Color?

Neutrophils, or white blood cells, help your body fight off infections.

Those cells release chemicals in response to invading bacteria or viruses, which may cause mild coloration in your mucus, Philip Chen, MD, an associate professor of otolaryngology and rhinology at the University of Texas Health Science Center at San Antonio, told Health.

Your body gets rid of white blood cells and the infection-causing bacteria or viruses through your mucus. White blood cells may cause yellow mucus. Green mucus typically results if there are a lot of white blood cells and other debris, said Dr. Chen.

What Color Should Snot Be?

Some environmental factors and health conditions are more closely linked to some mucus colors than others, such as:

• Brown: Dried blood or inhaling something brown, such as dirt or cigarette smoke, may cause brown mucus. You may notice brown mucus if small amounts of blood are in your nasal passages or the air is dry, said Dr. Chen. Typically, brown mucus is normal and not harmful.
• Black: This can result from inhaling something dark, such as dust or cigarette smoke. Black mucus may be a symptom of a fungal infection in rare cases.
• Pink or red: Blood is the primary reason if your mucus is pink or red. An injury to your nose or too much friction from blowing or rubbing your nose may be the culprit. Other times, pink or red mucus may result from dry air.

Does Green Mucus Mean Infection?

Your mucus is generally clear, "but some mild coloration is not typically cause for alarm," said Dr. Chen. Green mucus may signal a bacterial or viral infection, but that's not always true.

You constantly breathe thousands of bacteria into your nasal passages, but those bacteria do not always make you sick. For example, you may notice mild coloration in your mucus if there's a build-up of harmless bacteria in your nasal passages.

Other times, green or yellow mucus signals an infection. Bacteria and viruses cause inflammation in your nasal passages, leading to excess mucus. A sign that an infection may be causing your green mucus is if it's thick and sticky. The build-up of infectious agents and white blood cells may thicken your mucus.

Does It Mean Viral or Bacterial Infection?

Mucus that is cloudy and more yellow than green may be likelier to be the result of a cold. Still, the color of your mucus alone cannot tell you whether your infection is bacterial or viral if you are sick.

Bacterial and viral infections often cause many of the same symptoms, like a cough, fever, and sore throat. A healthcare provider may administer tests to see what’s causing your infection, but mild symptoms are generally treatable at home.

Of note: Green mucus is not necessarily a sign of COVID-19. Still, green mucus may suggest infection if you have other COVID-19 symptoms.

Other common symptoms of COVID-19 include:

• A new loss of smell or taste
• Body aches
• Chills
• Cough
• Fever
• Gastrointestinal (GI) symptoms, such as diarrhea, nausea, and vomiting
• Chills
• Fatigue
• Sore throat
• Trouble breathing

Consider taking a COVID-19 test if you are blowing your nose a lot and had recent exposure to the virus.

A Quick Review

You likely do not need to see a healthcare provider if you have green mucus but otherwise feel fine. Other symptoms, like body aches, fever, and a runny or stuffy nose, may signal an infection. Consult a healthcare provider if your symptoms do not go away or worsen.