Snot and Mucus Decoded: The Meaning of Snot Colors
Booger, mucus, runny nose—whatever you call it, it is still gross. But did you know the color of your snot can tell you a lot about what is going on inside your body?
Excess mucus can be caused by allergies, viral infections, and bacterial infections, and the colors can vary wildly with all of these conditions as well.
What does your snot say about you?
Do you know what boogers are?
Boogers are made of dirt and dust that has gotten stuck inside your nose. The mucus covers it, and it eventually dries up.
This article will go into more detail about the different colors of snot and what they can mean; but first, a few commonly asked questions:
What Does Bright Yellow Snot Mean?
Though the color of your snot is by no means a definitive way to diagnose an illness, bright yellow snot generally indicates that your body is fighting off an infection of some kind. At the beginning of a cold (which usually lasts 10 - 14 days), the snot may be the brightest, possibly turning green or darker yellow after that.
Green vs. Yellow Snot
You can have an infection and not have green snot, or you could not have an infection and have green snot. There is no direct correlation between the type of infection and the color of snot, though the color of your snot may give some indication as to the length of your infection.1
What About Orange Snot?
Very yellow or golden snot can sometimes look orange, and sometimes a little blood mixed in with the yellow snot can also cause it to have an orange-y appearance.
Snot Color Meaning Chart
This is normal, though excess clear mucus could indicate allergies
If caused by allergies, take antihistamines.
Dairy consumption or congestion
Usually resolves itself
Your body fighting off a virus or cold
See your doctor if it lasts more than a week or you develop a fever.
Viral, bacterial, or fungal infection
See your doctor if it lasts more than a week or you develop a fever.
The bacteria Pseudomonas pyocyanea
See your doctor if it lasts several days.
Orange, red, or reddish-brown
See your doctor if it lasts several days or if there is a lot of blood
Black or gray
Dirt, dust, or pollution
Stay indoors when pollution is bad.
What Is Mucus, Anyway?
It lines the nose as well as other organs,2 acting as a guard against bad stuff that might enter the body, such as dirt and germs. It is made of water, cells, salts, and mucin, which is a glycoprotein.
It goes by different names depending on its location in the body. Here are some terms you may hear, all referring to mucus found in the upper respiratory system:
- Snot—the stuff coming from the nose.
- Phlegm—the stuff in your throat and anything that you might cough up.
- Sputum—a coughed-up mixture of mucus and saliva.
- Postnasal drip—the stuff that flows from the nasal cavity down the throat.
Mucus Decoded: In Depth
Its color and texture can indicate what is going on in the body and can be signs of a virus, infection, or other problem. Read below to find out what the color of your mucus may mean.
Normal mucus is a clear color and is thick and viscous, similar to the texture of glue. You probably don’t have any infection or virus if your snot is clear.2 As long as your body isn’t producing too much or too little of it, and as long it is the right texture, you should be in good health.
If your body is producing an excess amount, the likely cause is allergies. Talk to your doctor about appropriate treatment.
If your snot is white, it usually means that you're congested.3 According to Cleveland Clinic, this can happen when your mucus loses moisture and is flowing more slowly due to the inflammation in your nostrils. The presence of white mucus alone is no cause for alarm and is considered normal. You could be congested for a number of reasons. Drinking milk can also cause your phlegm to thicken, thus turning it white.4
Though it might thicken your phlegm, dairy will not increase your phlegm production. Though many people think otherwise, a study published in the American Review of Respiratory Disease found that drinking milk does not increase mucus production.5
The Phlegm-Dairy Connection
Did you know that the body produces about a liter of mucus a day?
Talk about being snotty.
If you have yellow snot, it can mean that you have a virus or a sinus infection and that your body is fighting something off. The color is produced by a type of white blood cell that responds to infections and inflammations.1 When the white blood cells die, they burst, releasing a green pigment. The green pigment mixes with the mucus, giving it the yellow color. The color is usually brighter at first, possibly even appearing neon yellow. It typically darkens over a few days.
Staphylococcus aureus bacteria typically produce a golden-yellow mucus. Dark yellow phlegm could mean bronchitis or another type of infection in the chest.
If it's yellow, that does not necessarily mean that you need to go to the doctor. It just means your body is fighting against something. Remember, as of yet, there is no cure for the common cold, and antibiotics will only clear up bacterial infections. Viral infections just have to run their course. The best cure is your body’s own defenses.
See a doctor if the symptoms worsen or last longer than a week. You should also see a doctor you have a fever, headache, or a phlegmy cough for more than a few days.
Green snot is actually just caused by a thicker concentration of the white blood cells that cause yellow snot. The color is usually brighter at first and darkens over a few days. Though conventional wisdom holds that yellow snot means virus and green snot means a bacterial infection, there is actually no scientific evidence to prove this.
Most doctors, in fact, don't even use mucus color as a reliable tool of diagnosis. Both green and yellow snot can result from viral infections. According to Dr. Matthew Rank, the color of snot is actually more of an indication of the length of symptoms if anything.5
A bacterial infection can result from a virus, however. When your sinuses become inflamed, they swell. This causes mucus to become trapped in your nasal passages. Over time bacteria and fungi can begin to grow in your sinuses, in which case you might need antibiotics.
If the symptoms have lasted more than 12 days or seem to be getting worse, see a doctor, especially if you are experiencing fever, cough with sputum, headache, and sinus pressure.2
Mucus can turn blue because of a certain bacteria called Pseudomonas pyocyanea, also known as Pseudomonas aeruginosa. It's fairly rare—about one in 10,000 stuffed-up people will have blue snot. If it changes to a thick blue color that lasts several days, you should see a doctor.
Blue can also happen if you have inhaled blue powder or something else blue in the air or because of some other contaminant. If this is the case, it should clear up within a day or two.
Did you know that you can have different colored mucus in each nostril?
There could be an infection or sore in one side that is not in the other. Now that's a nose of a different color.
If your mucus is tinged red or reddish brown, it is usually a sign of blood.2 The presence of blood is not necessarily a cause for alarm. The blood can come from a variety of causes. For example:
- When the sinuses become inflamed, they can begin to bleed.
- Frequent nose-blowing can cause sores to form at the base of the nose. Taking care to blow and wipe the nose gently can prevent this.
- The tiny blood vessels in the nasal passages break easily, causing blood-tinged mucus. This can happen if the air is too dry, in which case using a saline spray to moisten the nasal passages will help.
- Picking or rubbing your nose can also cause your snot to have a little blood in it.
- If you are coughing up red or brown phlegm, it could be a sign of bronchitis.
- Smoking can also irritate nasal passages, leading to slight bleeding. This, combined with tiny tobacco particles, will turn it a reddish-brown.
While a little bit of blood in your snot is not a problem, if you're blowing out large volumes of it, you should see a doctor.1
If there is a significant amount of blood that has lasted several days, you should see a doctor to determine the cause of the blood and whether treatment is necessary.
Brown or brownish-red snot is typically associated with smokers. It is mixed with particles from the cigarettes. Smoking can also irritate nasal passages, leading to slight bleeding. Smoking can also cause people to cough up the brown/red phlegm rather than just blowing it out of their noses.
The way to ease the production of brown phlegm is to smoke less.
Inhaling dust and dirt, while often leading to gray or black mucus, sometimes can also give it a brown tinge.
Black or Gray
Dark-colored mucus generally happens from inhaling pollutants in the air. The job of the mucus is to trap dirt or other particles and prevent them from getting further into the body. If there is ash, dirt, dust, smoke, or similar substances in the air, your nose will trap it.
Did you know that you could have purple, pink, or even blue snot?
Mixing up a pitcher of Kool-Aid can turn your snot the color of the drink if you accidentally breathe in a bit of the powder. Be careful not to breathe in powders, though. Those tiny particles are meant to go in your drink, not in your lungs!
How to Ease Cold Symptoms
Typically, a virus begins by producing an abundance of clear mucus, which turns a bright yellow or greenish color, then darkens over a period of a few days, usually turning somewhat green. At the end of the virus, it may turn a brown/red color. It should then start clearing up, becoming less thick until it returns to normal.
Ways to ease your symptoms:
- Use nasal sprays, such as saline sprays, to keep the passages moist.
- Drink plenty of fluids to thin the mucus and keep your upper respiratory system moist.
- Don't starve a cold. Eating nutritious meals when you're sick is important. Your body needs the energy to fight off the bug.
- Ease fever and body aches with Tylenol.
- Reduce swelling and any inflammation with Ibuprofen.
- Steam and hot liquids can help ease congestion.
- Take Mucinex or another decongestant to loosen the phlegm and make coughs more productive.
- Suck on cough drops to keep the throat moist. A spoonful of honey also can help alleviate the cough.
- Take antihistamines to help alleviate the symptoms of a cough if it is caused by allergies.
- See a doctor if you develop a fever that lasts for more than two days
- Avoid smoking and second-hand smoke.
Remember, strange-colored mucus doesn't always mean there is a problem. You should only be worried if it persists for over 12 days, especially when other symptoms such as fever, headache, and cough are present.
Of course, these colors are just an indication of what could be wrong, not a precise diagnosis. You can still have an infection even with clear mucus. If you are concerned about something with your body, see a doctor.
So what color is your snot anyway?
How to Ease Cold Symptoms
How Much Do You Know About Snot?
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- Shmerling, Robert H, MD. "Don't Judge Your Snot By Its Color." February 8, 2016. Harvard Health Publications. Accessed April 3, 2017.
- Watson, Stephanie. Reviewed by Luqman Seidu, MD. "The Truth About Mucus." April 10, 2014. WebMD. Accessed April 3, 2017.
- Reviewed by Raj Sindwani, MD. "What the Color of Your Snot Really Means (Infographic.)" November 28, 2014. Cleveland Clinic. Accessed April 3, 2017.
- "Milk Products and Mucus in COPD." (n.d.) COPD Foundation. Accessed April 3, 2017.
- Pinnock, Graham, Mylvaganam, and Douglas. "Relationship between milk intake and mucus production in adult volunteers challenged with rhinovirus-2." Feb 1, 1990. American Review of Respiratory Diseases. Accessed April 3, 2017.
- Nierenberg, Cari. "You Think It's Mucus, but It's Not." December 10, 2008. ABC News. Accessed April 3, 2017.