What are the Most Common Causes of Vomiting Mucus?

Meghan Cunningham
Meghan Cunningham
Allergies may cause individuals to vomit mucus.
Allergies may cause individuals to vomit mucus.

The three most common causes of vomiting mucus are colds, allergies, and acid reflux. In respiratory situations, the mucus is usually dripping down from the sinuses and nasal passageways into the throat. When there’s enough of it, this can cause gagging and ultimately vomiting. Children tend to be some of the most vulnerable to mucus-filled vomit in these cases since their gag reflexes often aren’t as developed as adults’ are. In the case of acid reflux, the mucus is usually flowing up from the stomach and digestive tract. While it can certainly be unsettling for people to see mucus in their vomit, it isn’t usually a cause for concern, and many experts actually say that it’s pretty common. In most cases it will go away on its own as soon as the root cause disappears.

Mucus Basics

Children may vomit mucus because of their sensitive gag reflex.
Children may vomit mucus because of their sensitive gag reflex.

Mucus is a fluid that is secreted by the body’s mucus membranes. It is a thick, gum-like substance that occurs normally in places like the respiratory and digestive tracts — places that depend on the constant movement of different particles. It coats the walls of the nasal passages to collect outside elements like dust or pollen that might irritate someone and cause him or her to sneeze, for example, and it lubricates the air passages, making it easier to breathe. In the esophagus and stomach it acts as a coating to protect these organs from stomach acid that is released as a normal part of digestion.

Clearing nasal passages with a neti pot may help prevent instances of vomiting mucus.
Clearing nasal passages with a neti pot may help prevent instances of vomiting mucus.

A healthy human body produces anywhere from a quart to a gallon (0.94 to 3.78 liters) of mucus a day. When illness strikes, though, production often goes significantly up, and this is when vomiting becomes more likely. Irritation often triggers an immune response in the body, prompting more mucus to help either flood out the bacteria or virus or block the way for its spread. Excesses that flow into the throat or esophagus often cause vomiting not as a result of any sort of independent stomach problem, but rather as a consequence of overload.

Respiratory Problems

Acid reflux may cause someone to vomit musucs.
Acid reflux may cause someone to vomit musucs.

People often produce the most mucus when they’re suffering from a cold, an upper respiratory infection, an allergy attack, or a coughing fit. In these instances, the mucus leaks from the sinuses and runs down the back of the throat — called “post-nasal drip” in medical circles — or is coughed up from the lungs; it may then be swallowed and end up in the stomach. When a person swallows too much of this secretion, it can cause vomiting as the body’s way of getting rid of it. Too much mucus or mucus that is very thick often causes nausea, too, and one of the body's natural responses is to trigger vomiting to ease that nausea.

Implications for Children

An illustration of a human stomach.
An illustration of a human stomach.

One of the biggest reasons young children sometimes fall prone to vomiting mucus is because of their generally sensitive gag reflex. A child with a cold, allergies, or a lung infection will typically secrete a great deal of mucus. That child may cough so forcefully trying to clear his or her airway that he or she triggers the gag reflex, and vomiting is often the inevitable result. In addition, children tend to swallow mucus rather than spitting it out or "coughing it clear" as adults do. This may occur when children have a severe infection, such as a sinus infection that creates thick, excessive secretions of mucus, or when they are too young to understand what’s happening.

Acid Reflux

Someone may vomit mucus as a result of a severe cold.
Someone may vomit mucus as a result of a severe cold.

Another cause of vomiting mucus may be due to acid reflux, which is also frequently called “heartburn” because of the burning, tight sensation it tends to cause in the upper chest. In people who suffer from heartburn, the stomach acid backs up into the esophagus. In order to protect itself, the body produces more mucus secretions. This excessive secretion is often swallowed back down into the stomach, and when there is too much, a person might feel ill and vomit up the excess.

Treatment and Prevention

A bad cough may cause someone to vomit mucus.
A bad cough may cause someone to vomit mucus.

There isn’t usually a cure for mucus vomiting and the condition will generally go away on its own as soon as the underlying cause — allergies, for instance, or a cough — disappears. People who have excessive mucus or find that they are constantly swallowing it or vomiting it back up may want to get the advice of a qualified healthcare provider, though. Certain medications can help keep mucus levels in check, which can reduce the risk of nausea and vomiting. Certain antacids can also help keep heartburn under control. Regularly clearing the nasal passageways and spitting rather than swallowing mucus that drips into the mouth can help, as well.

Constant mucus secretions and vomiting that seems to happen outside of some other identifiable condition may indicate some more serious condition, and should usually be evaluated. Infants and young children should also usually be treated for persistent mucus secretions to avoid the risk of choking, particularly during the night.

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Discussion Comments


I have had an upper respiratory infection and now I get cramps and noticed some vomiting after eating or before eating. Also when I laugh really hard, I throw up clear mucus. I also get cramps in my stomach and feel really fatigue. P.S. I work and go to school plus I stay up late, but I’ve never been this exhausted. Should I be worried? My body feels warm to the touch at times and the lymph nodes under my neck hurt.


I will wake up in the morning, and sometimes throw up after coughing. It's a yellowish/greenish liquid which doesn't burn. I also randomly wake up with terrible heartburn. Thanks for the enlightening article. I'm going to work on the heartburn, and I've been taking allergy medicine which has been helping a bit.


Does your baby drink water? I started giving my daughter water at night two days ago and she threw up all the mucus she had been swallowing tonight around 4 a.m. I'm glad I was awake. Otherwise, she might have choked on it in her sleep. She had a severe cough but all she could do was swallow the phlegm. She isn’t smart enough to spit it out yet. She’s only 13 months old.

I just think about how I feel when I forget to drink water and drink milk and other things like soda, etc. I get thick mucus. On top of the cold she had, I kind of put it together. I got her diet and sleeping perfect also during this water binge and I think I'm going to continue it. She isn’t coughing in her sleep anymore. That usually kept her awake. Since she threw up two hours ago, I'm just sitting here watching her while browsing the net about it.

Don’t slack on taking the time to feed your child nutritious things rather than just handing them a bottle. My daughter will act like she doesn’t want the bottle, but will devour some Gerber or cereal 80 percent of the time (she will eat my food anytime, even after she is full and I try to sneak my meal, but I always give her some just to boost the diversity of her diet and to fill her up). Sometimes though, she wants a bottle and she actually drinks water pretty well (better than I thought she would) with a little infant spoon of sugar added to about 3-4 ounces of water.

I try to get her sunlight anytime it’s warm out. I’m waiting for the weather to stop fluctuating so she doesn’t get sick again! I think that’s healthy for her. For some reason, the sun, the breeze, the buzzing and moving calms her cold down, but I'm crossing my fingers not trying to jump the gun, but I think her mucus is gone, after the amount she threw up. She had just eaten, but still only threw up mucus -- none of the cereal or rice and noodles she had eaten, just mucus immediately after she ate in the middle of the night. She didn’t want a bottle, which is unusual. She loves them at night because she doesn’t have to open her eyes. She was crying and coughing so hard I felt sad but I've always wanted her to spit that damn mucus out. I even tried timing it and fingering it out when she got that distinctive, good, hacking cough sound going but she swallows it fast. I can’t even see what it is with her tongue. The only thing I can think that could have also helped that I forgot to mention was I gave her an inhaler of proair hfr albuterol sulfate earlier in the night to just free the mucus (they say four times a day, but I don’t just so she doesn’t become dependent on it). I guess just when I think about it, I do it. That all could have combined with her not wanting to be awake and having a snotty cry. But she literally hasn’t coughed.


Can anyone help? I have read all the posts and nothing I can find relates to me. I had a really bad cold and after the symptoms of the cold passed, I have had a persistent, dry cough followed by vomiting clear fluid. It happens at any time, sometimes up to six times a day.


I have copd and a very bad nasal drip causing me to have excessive mucus in my throat and today I am throwing up bile. Should I go to the emergency?


There is a condition called MALT. It stands for Mucosally Associated Lymphatic Tissue. Patches of tissue in the esophagus and stomach can become so irritated by repetitive exposures to endocrine system disruptive chemicals, from consumer products and environmental toxins, that they will dramatically react by excessively producing this thick "protective" mucosa.

In many cases you can eliminate the reaction by removing all toxins from your diet and environment. Some fragrances are major triggers, as are excitotoxins like MSG and aspartic acid, found in "flavors," seasoning mixes and meat tenderizers. Excito-toxins are also found in "broth" components of pet food. Stress can make the reaction worse.


My dog has recently started vomiting mucus and the vet says he probably has indigestion from bolting his food. We recently got a puppy and there's a bit of jealousy going on there I think.

As we have a big yard it would have been easy to miss what was happening, so I've learned to keep a close eye on what he's up to after eating.

Having read this article I realize there are many other potential causes for dog vomiting. I would hate for him to be throwing up because he has a cold or chest infection and I didn't catch on.


My friend's mother got pneumonia last year and was quite sick for a few weeks. Then one day she started throwing up green mucus and recovered pretty much instantly!

I'm happy for her of course, but a little tired of hearing the story of the miracle mucus. I would never have thought of this as a positive thing to be doing.

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    • Allergies may cause individuals to vomit mucus.
      By: FedeCandoniPhoto
      Allergies may cause individuals to vomit mucus.
    • Children may vomit mucus because of their sensitive gag reflex.
      By: dalaprod
      Children may vomit mucus because of their sensitive gag reflex.
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      By: Nadia Ivanova
      Clearing nasal passages with a neti pot may help prevent instances of vomiting mucus.
    • Acid reflux may cause someone to vomit musucs.
      By: pathdoc
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    • An illustration of a human stomach.
      By: pixologic
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    • Someone may vomit mucus as a result of a severe cold.
      By: jedi-master
      Someone may vomit mucus as a result of a severe cold.
    • A bad cough may cause someone to vomit mucus.
      By: ramonespelt
      A bad cough may cause someone to vomit mucus.