What Causes Vomiting?

Whether you call it vomit, throw up, barf, puke, hurl or heave, one thing’s for sure: there’s nothing fun about vomiting. As if the sensation of vomiting isn’t bad enough, the cause of your vomiting can be difficult to diagnose. 

Vomiting is a symptom that indicates a whole host of possible diseases, disorders and illnesses. Online, you will find dozens of hypothetical vomiting causes and reasons this bodily mechanism was triggered. 

In this article, we’ll take an in-depth look at some of the most common causes of vomiting and offer some ideas on how to stop vomiting.  

Nine causes of vomiting 

Vomiting signals that something abnormal is happening in the body. It’s a natural way for the body to try to correct the imbalance by ridding itself of the problem.  

There are many sudden vomiting causes, but some are more common than others. Here are a few that you may have experienced.  

1. Nausea 

Nausea is an uncomfortable gastrointestinal sensation that makes a person feel like they will vomit. Scientists have not agreed upon how the brain processes the sensation, but almost everyone has experienced nausea at some point.  

Fortunately, nausea does not always lead to vomiting. It can be a symptom of an underlying condition. However, depending on the severity it might stimulate vomiting.  

2. Retching 

Retching is when the stomach repeatedly contracts and what many people describe as “dry heaving,” or the feeling of vomiting without losing stomach contents. Physiologically, it’s spasmodic respiratory movements with a closed glottis, the space between the vocal cords in the larynx. 

While retching is not a vomiting cause, the spasms are often a sign of what’s to come and can eventually lead to productive sudden vomiting. 

3. Gastroenteritis 

When people talk about the stomach flu or a stomach bug, they are talking about bacteria or viruses that sometimes attack the gastrointestinal (GI) system. These infections lead to gastroenteritis, an inflammation of the GI system, which may cause vomiting. 

The norovirus is the most common cause of gastroenteritis. With over 19 million cases a year, norovirus is extremely contagious and often causes nausea and vomiting

The virus is transmitted by touching your nose, mouth or eyes after coming into contact with someone who carries the infection. It can also be caused by eating food contaminated with the virus. 

Typically, norovirus causes one to three days of discomfort until the body rids itself of the infection. It’s a common cause of vomiting, but there isn’t anything you can do aside from taking care of yourself as the virus runs its course. It’s important to stay hydrated, follow the B.R.A.T. diet, and avoid caffeine and alcohol. 

If life-threatening symptoms are experienced, visit the ER as soon as possible. 

4. Food poisoning 

Unsafe food handling is a common but potentially serious mistake. Whether you ate some food left out overnight or fearlessly downed questionable sushi, food poisoning is another cause of vomiting. Over 48 million Americans get sick every year from eating contaminated food.  

Food poisoning is a general term for one of many nonspecific bacteria or viruses transmitted through food. Typically, when talking about food poisoning, we’re talking about food contaminated with a bacterium like E. coli, listeria or salmonella. 

The body can usually clear itself of the bacteria within 48 hours. Vomiting is typically the path to ridding itself of the bacteria, and often throwing up after eating is paired with nausea. In some cases, you may need antibiotics, which can be acquired after a visit to urgent care. 

At home, food poisoning can typically be avoided. Follow food safety guidelines, including proper handwashing, cooking foods to recommended temperatures and throwing away potentially unsafe food. 

5. Motion sickness 

Motion sickness is a sensation triggered when there’s a difference between motion sensed by your inner ear and the motion you see with your eyes. Actions like reading in the car or being on a boat in choppy water can lead to motion sickness.  

This discrepancy between how your sensory system perceives the world around you can lead to nausea, which can cause sudden vomiting. Fresh air and deep breathing sometimes ease these symptoms, but avoiding situations that cause motion sickness might be necessary.  

6. Pregnancy 

Although morning sickness and nausea during pregnancy are common, researchers are not entirely sure what causes them. The most common theory is the number of physical changes in the body occurring during a pregnancy. Between hormonal changes to stress, there are several causes. 

Many call it “morning sickness,” but the truth is that nausea can strike at any time of day during pregnancy. Nausea may begin as early as the fourth week of pregnancy. Approximately half of the women who experience nausea during pregnancy feel relief around 14 weeks. 

Nausea and vomiting are considered normal parts of pregnancy, but severe cases can be unsafe for you and the baby. Talk to your healthcare provider if you’re concerned about dehydration or lack of nutrition.  

7. Acid reflux 

Acid reflux is a malfunction of the body’s digestive system, in which the lower esophageal sphincter (LES) leaks and allows stomach acid and undigested food to travel back up your esophagus. The sour taste from stomach acid can sometimes be a cause of vomiting. 

Acid reflux symptoms can sometimes be relieved with lifestyle changes. Those with symptoms should avoid fried foods, citrus, spicy foods, caffeine, sodas and alcohol, which may weaken the LES. Experts also recommend quitting smoking, elevating your upper body when sleeping and not lying down within two hours after eating.  

Talk to your provider about using medications like antacids to relieve acid reflux. 

8. Stress 

Have you ever felt queasy just before making a speech? Maybe you’ve had butterflies in your stomach right before confessing your feelings to a crush. Real-world events can cause stress, and that may trigger a physical reaction like nausea or even vomiting. 

These symptoms are part of your autonomic nervous system, which moderates heart rate, blood pressure and digestion. Anxiety, fear or excitement can cause your body to go into “fight or flight” mode, which leads to vomiting in some people.  

When faced with stressful situations, breathing techniques are often helpful. Try taking deep breaths through the nose and exhaling slowly through the mouth.  

9. Migraine headaches 

Migraine headaches are severe headaches that can trigger nausea, vomiting and light sensitivity. Certain foods, hormonal changes, alcohol, smoking, stress, lack of sleep or certain odors might trigger them.  

A migraine headache can be treated with rest and may require over-the-counter or prescription pain medication.  

When you feel a migraine coming on, it is best to rest in a dark room and try to sleep. Avoid caffeine and alcohol. If you do vomit, try to sip water to stay hydrated.  

Speak to your doctor about pain medication to help manage migraines if you are experiencing them frequently.  

Signs of more serious issues 

Sometimes vomiting can be a sign of a more serious issue. It may be a sign of: 

  • Appendicitis 
  • Bleeding of GI tract 
  • Cancer or tumor 
  • Heart attack 
  • Intestinal blockage 
  • Kidney or liver disease 
  • Stomach ulcers 

 If you can’t control your vomiting or it does not improve within a day or two, it is important to see a healthcare provider for an evaluation. 

What does blood in vomit mean?  

Blood in vomit is called hematemesis and is a serious symptom. It could mean you have internal bleeding in your upper GI tract, which can lead to hypovolemic shock from losing too much blood. Keep in mind that the blood may not be bright red, especially if the problem is happening in your stomach or intestine. Instead, it may look darker and brownish, like coffee grounds. If you vomit blood, it is best to seek medical attention immediately.   

What causes bile vomiting? 

Throwing up bile could be an indication of a more serious problem like alcoholism, food poisoning, intestinal blockage, hernias and bile reflux, which can cause people to vomit bile. Bile is a greenish, acidic liquid your liver typically makes for digestion. If you vomit while your stomach is empty of food, bile might be what comes up. These conditions need a medical professional's evaluation to provide the proper treatment. 

How to stop vomiting or prevent it 

While it’s never pleasant, sometimes vomiting is a necessary function that protects your body. For example, consuming enough alcohol to achieve a toxic level in your bloodstream often results in vomiting. In this circumstance, throwing up is your body’s attempt to return to a nontoxic level that might otherwise damage your brain and other organs.  Another example is when the body vomits to rid itself of a viral or bacterial infection like E. coli. This is another vomiting cause that may need to run its course.  

However, if you’re experiencing nausea due to motion sickness, pregnancy or stress, it might be possible to prevent the vomiting stage. 

Try some of these tips for nausea control: 

  • Avoid alcohol, caffeine and acidic drinks like orange juice 
  • Avoid oily and spicy foods 
  • Avoid physical activity 
  • Get some fresh air by opening a window or stepping outside 
  • Remove outer layers of clothing if you’re feeling warm 
  • Sit down or lie propped up 
  • Sip something carbonated like cold ginger ale  
  • Suck ice chips or have a cold drink 
  • Practice deep breathing  

Vomiting FAQs 

Here are some frequently asked questions about vomiting.  

Is a little blood in vomit normal?  

Any amount of blood in vomit is typically a sign that something more serious is going on that will require a medical evaluation.  

Does strep cause vomiting?  

Yes, vomiting, nausea and stomach pain can be symptoms of strep throat

When should you go to the ER for vomiting?  

You should go to the ER for vomiting when you have been throwing up for more than two days, have signs of dehydration, are vomiting uncontrollably or your vomit contains bright red or brown colored blood.  

What do the different colors of vomit mean?  

Vomit can be different colors depending on what you eat. Red or dark-colored vomiting could be a sign of blood in your vomit. Green or yellow vomit is a sign of bile in the vomit. 

When to visit an urgent care for vomiting 

People vomit for many reasons, but the severity of the situation should determine whether to seek medical help. Something like food poisoning is typically not anything to worry about — just let it run its course. The same goes for bouts of motion sickness and stress vomiting. 

Although vomiting and nausea are never comfortable, there’s a sizable difference between life-threatening symptoms and the overall discomfort of retching. Unless your vomit shows traces of blood, you can likely seek medical care at your local urgent care rather than the ER. 

If accidental poisoning occurs from medicines, household chemicals, cleaners or pesticides, call the Poison Control Centers national hotline at 1-800-222-1222 or visit a local urgent care center near you. You can walk in without an appointment or save your spot online. We’ll have you back to feeling better in no time. 



  1. https://my.clevelandclinic.org/health/symptoms/8106-nausea--vomiting 
  2. https://www.cdc.gov/norovirus/index.html 
  3. https://www.cdc.gov/foodborneburden/index.html 
  4. https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/steps-keep-food-safe 
  5. https://medlineplus.gov/ency/patientinstructions/000604.htm 
  6. https://www.niddk.nih.gov/health-information/digestive-diseases/acid-reflux-ger-gerd-adults 
  7. https://medlineplus.gov/ency/patientinstructions/000420.htm 
  8. https://www.cdc.gov/groupastrep/diseases-public/strep-throat.html 

Written by Sarah Thebarge, Physician Assistant