Table of ContentsView AllTable of ContentsThe Purpose of PukeBrain-Related CausesGut-Related CausesIdentifying the CauseFrequently Asked Questions

Table of ContentsView All

View All

Table of Contents

The Purpose of Puke

Brain-Related Causes

Gut-Related Causes

Identifying the Cause

Frequently Asked Questions

As miserable asnauseamay make you feel, throwing up has a function. To figure out what’scausing your nausea, it helps to understand why we ever have to vomit in the first place.

Verywell / Cindy Chung

Potential Causes of Nausea and Vomiting

Your body has evolved to protect you. One protective mechanism protects you from toxic things you might ingest.

When you eat something toxic, several triggers give you nausea (theurge to vomit.) Taste and smell are two of the most powerful. If it smells or tastes nasty, your body may reject it as dangerous.

Seeing, smelling, or hearing someone else vomit can make you vomit, too. Your body is programmed this way because if everyone in your group ate the same thing and it made someone sick, you could be next.

But what if nobody else got sick or if you’re all alone? You could still have eaten something bad for you. If it triggers trouble in the brain—especially dizziness—then your gut will throw it out, fearing poison that could cause it trouble.

While vomiting has numerous causes, they all boil down to three basic things:

Things irritating the gut are more common than things irritating the brain, so why does the brain get top billing?

Well, it’s the brain. If you suddenly have nausea, or you vomit without first feeling nauseated, something bad might be happening inside your cranium, and that’s not good.

What Is Emetophobia? The Fear of Vomiting

Your brain works in a very narrow range of happiness. If it gets too much sugar, it doesn’t work right. If it doesn’t get enough sugar, it doesn’t work right.

It’s too finicky to dine on fat and it needs a certain amount of oxygen. It can’t be too warm or too cold and it can’t be under too much pressure or too little. Basically, brains are high maintenance.

A brain injury that causes swelling inside your skull almost always triggers vomiting, even though that probably can’t help the brain in any way. It’s an unintended result of the body thinking any problem with the brain is due to something you ate.

However, knowing that brain malfunction can result in puking reminds us to consider brain problems whenever nausea shows up for no apparent reason. Some brain-affecting things trigger nausea more often than others, including:

Anatomy of the Brain

The mechanism that makes thedigestive tract(the gut) want to vomit is complicated, but essentially, the point is to evacuate the stomach when something in there is dangerous to you.

That’s why bacteria, viruses and all sorts of toxins can trigger nausea and vomiting from the gut level. The most common causes of nausea related to the gut are:

Prenancy-Related NauseaMorning sicknessis a common symptom of pregnancy, and it can actually occur at any time of the day. If you’re nauseous and think you could be pregnant, a home pregnancy test and/or a trip to the doctor can tell you for sure.

Morning sicknessis a common symptom of pregnancy, and it can actually occur at any time of the day. If you’re nauseous and think you could be pregnant, a home pregnancy test and/or a trip to the doctor can tell you for sure.

How to Safely Make Yourself Throw Up

Ultimately, the best way to identify the cause of your upset stomach is to rule out the easiest stuff first: Have you been drinking? Are you pregnant? Are you on a boat?

If not, then look for some additional telltale symptoms.

Cyclic Vomiting Syndrome (CVS): How Treatment Helps Manage Episodes

A Word From Verywell

The precise biological reason for this is unclear. However, scientists theorize it is an evolutionary reaction. If everyone in the tribe ate the same food and it made one person sick, the others in the group could also be at risk of poisoning, so the body rejects the stomach contents as protection.

Yes, COVID can cause gastrointestinal symptoms, but it doesn’t always. Coronavirus can have a wide variety of symptoms. In one review of studies, the rate of gastrointestinal symptoms in COVID cases ranged from 2% to 79%.Scientists aren’t sure why this is.One possible explanation is vomiting may be more prominent with some variants of the virus than others. For instance, vomiting appears less common with the Delta strain and more common with the Omicron variant.

Yes, COVID can cause gastrointestinal symptoms, but it doesn’t always. Coronavirus can have a wide variety of symptoms. In one review of studies, the rate of gastrointestinal symptoms in COVID cases ranged from 2% to 79%.Scientists aren’t sure why this is.

One possible explanation is vomiting may be more prominent with some variants of the virus than others. For instance, vomiting appears less common with the Delta strain and more common with the Omicron variant.

How to Treat Nausea

7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.UptoDate.Patient education: Nausea and vomiting of pregnancy (Beyond the Basics).Centers for Disease Control and Prevention.Symptoms of mild TBI and concussion.Singh P, Yoon SS, Kuo B.Nausea: a review of pathophysiology and therapeutics. Therap Adv Gastroenterol. 2016;9(1):98-112. doi:10.1177/1756283X15618131Centers for Disease Control and Prevention.Carbon monoxide poisoning basics.Centers for Disease Control and Prevention.Signs of heat-related illnesses.Centers for Disease Control and Prevention.About Food Safety.Wang MK, Yue HY, Cai J, et al.COVID-19 and the digestive system: A comprehensive review.World J Clin Cases. 2021;9(16):3796-3813. doi:10.12998/wjcc.v9.i16.3796Additional ReadingFarmer AD, Ban VF, Coen SJ, et al.Visually induced nausea causes characteristic changes in cerebral, autonomic and endocrine function in humans.J Physiol. 2015;593(5):1183-1196. doi:10.1113/jphysiol.2014.284240Norton DM, Brown LG, Frick R, et al.Managerial practices regarding workers working while ill.J Food Prot. 2015;78(1):187-195. doi:10.4315/0362-028X.JFP-14-134

7 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.UptoDate.Patient education: Nausea and vomiting of pregnancy (Beyond the Basics).Centers for Disease Control and Prevention.Symptoms of mild TBI and concussion.Singh P, Yoon SS, Kuo B.Nausea: a review of pathophysiology and therapeutics. Therap Adv Gastroenterol. 2016;9(1):98-112. doi:10.1177/1756283X15618131Centers for Disease Control and Prevention.Carbon monoxide poisoning basics.Centers for Disease Control and Prevention.Signs of heat-related illnesses.Centers for Disease Control and Prevention.About Food Safety.Wang MK, Yue HY, Cai J, et al.COVID-19 and the digestive system: A comprehensive review.World J Clin Cases. 2021;9(16):3796-3813. doi:10.12998/wjcc.v9.i16.3796Additional ReadingFarmer AD, Ban VF, Coen SJ, et al.Visually induced nausea causes characteristic changes in cerebral, autonomic and endocrine function in humans.J Physiol. 2015;593(5):1183-1196. doi:10.1113/jphysiol.2014.284240Norton DM, Brown LG, Frick R, et al.Managerial practices regarding workers working while ill.J Food Prot. 2015;78(1):187-195. doi:10.4315/0362-028X.JFP-14-134

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

UptoDate.Patient education: Nausea and vomiting of pregnancy (Beyond the Basics).Centers for Disease Control and Prevention.Symptoms of mild TBI and concussion.Singh P, Yoon SS, Kuo B.Nausea: a review of pathophysiology and therapeutics. Therap Adv Gastroenterol. 2016;9(1):98-112. doi:10.1177/1756283X15618131Centers for Disease Control and Prevention.Carbon monoxide poisoning basics.Centers for Disease Control and Prevention.Signs of heat-related illnesses.Centers for Disease Control and Prevention.About Food Safety.Wang MK, Yue HY, Cai J, et al.COVID-19 and the digestive system: A comprehensive review.World J Clin Cases. 2021;9(16):3796-3813. doi:10.12998/wjcc.v9.i16.3796

UptoDate.Patient education: Nausea and vomiting of pregnancy (Beyond the Basics).

Centers for Disease Control and Prevention.Symptoms of mild TBI and concussion.

Singh P, Yoon SS, Kuo B.Nausea: a review of pathophysiology and therapeutics. Therap Adv Gastroenterol. 2016;9(1):98-112. doi:10.1177/1756283X15618131

Centers for Disease Control and Prevention.Carbon monoxide poisoning basics.

Centers for Disease Control and Prevention.Signs of heat-related illnesses.

Centers for Disease Control and Prevention.About Food Safety.

Wang MK, Yue HY, Cai J, et al.COVID-19 and the digestive system: A comprehensive review.World J Clin Cases. 2021;9(16):3796-3813. doi:10.12998/wjcc.v9.i16.3796

Farmer AD, Ban VF, Coen SJ, et al.Visually induced nausea causes characteristic changes in cerebral, autonomic and endocrine function in humans.J Physiol. 2015;593(5):1183-1196. doi:10.1113/jphysiol.2014.284240Norton DM, Brown LG, Frick R, et al.Managerial practices regarding workers working while ill.J Food Prot. 2015;78(1):187-195. doi:10.4315/0362-028X.JFP-14-134

Farmer AD, Ban VF, Coen SJ, et al.Visually induced nausea causes characteristic changes in cerebral, autonomic and endocrine function in humans.J Physiol. 2015;593(5):1183-1196. doi:10.1113/jphysiol.2014.284240

Norton DM, Brown LG, Frick R, et al.Managerial practices regarding workers working while ill.J Food Prot. 2015;78(1):187-195. doi:10.4315/0362-028X.JFP-14-134

Meet Our Medical Expert Board

Share Feedback

Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit

Was this page helpful?

Thanks for your feedback!

What is your feedback?OtherHelpfulReport an ErrorSubmit

What is your feedback?