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What’s Causing Your Nausea and Vomiting?

Nausea is usually caused by a stomach bug, the flu, COVID, and food poisoning. But other common causes are motion sickness, migraines, GERD, a hangover from too much alcohol, and morning sickness in pregnant women. A more serious cause is gallstones. There are medications you can take to quell nausea, after ruling out serious causes.
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Last updated May 13, 2024

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13 most common cause(s)

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Pregnancy Problems
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motion sickness
Acute Gastritis
Food Poisoning
Brain Tumor
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Bowel obstruction
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Brain/head injury

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What are nausea and vomiting?

Nausea causes stomach discomfort and the feeling like you may vomit. Sometimes, you even do throw up. It can be for a moment (like after smelling a bad odor), temporary (like during a stomach bug), or lasting (chronic).

Vomiting is when the body forcefully gets rid of what's in the stomach by bringing it back up and out through the mouth. You almost always feel nauseated before vomiting.

Nausea, with or without vomiting, is most commonly caused by a stomach bug and food poisoning. Pregnant women often feel nauseous—or even vomit—during their first trimester.

Other causes include motion sickness, migraines, drinking too much alcohol, and side effects from medications. Sometimes, it is caused by an underlying condition, like an ulcer, gallbladder disease, or heart attack.

There are medications to treat nausea if needed. But when nausea is a symptom, the treatment is usually for the underlying problem.


1. Infections


  • Nausea and vomiting
  • Diarrhea
  • Crampy abdominal pain
  • Possible dehydration

There are many viral infections that may cause nausea. And most, including the flu and COVID-19, may also cause vomiting, diarrhea, and abdominal pain.

Both norovirus and rotavirus are highly contagious viruses that cause nausea, vomiting, and diarrhea. They are sometimes referred to as the “stomach flu” or “stomach bug.”

Antibiotics do not work for viral infections. Instead, you want to treat your symptoms. Because you may lose a lot of fluids if you are vomiting or have diarrhea, drink plenty of liquids to avoid dehydration.

To reduce nausea, eat more frequent, smaller, bland meals. If your symptoms are severe or you are unable to drink enough fluids, your doctor may recommend anti-diarrheal or anti-nausea medication. In severe cases of dehydration, you may need to go to the ER for medications and fluid through an IV.

2. Food poisoning

Should I be worried if I can’t eat or drink?

“Let your doctor know if your nausea is interfering with your ability to eat and drink enough. This can lead to dehydration and nutritional deficiencies.” —Dr. Chandra Manuelpillai


  • Nausea or vomiting
  • Diarrhea
  • Abdominal cramps

Food poisoning is caused by eating something contaminated with bacteria. Symptoms come on very quickly—usually within 30 minutes to a few hours after eating—and typically last for about 24 hours.

There is no specific treatment besides avoiding dehydration by drinking fluids and eating bland food. Anti-diarrheal medications are not recommended since diarrhea is your body’s way of getting rid of toxins. Anti-nausea medications are given to people who are becoming dehydrated because they can’t keep liquids down. Symptoms usually do not last long, so most people should recover on their own.

3. COVID-19


  • Fever or chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Fatigue
  • Muscle or body aches
  • Headache
  • Loss of taste or smell
  • Sore throat
  • Congestion or runny nose
  • Nausea or vomiting
  • Diarrhea

COVID-19 is a dangerous disease caused by a coronavirus, and it is highly contagious. It infects the respiratory tract (including your nose, throat, sinuses, and lungs). But it can also affect other organs including the brain, blood vessels, and the skin. It can cause flu-like symptoms.

In many people, COVID-19 can have mild symptoms, but others can become severely ill and die from the disease.

Rest and drinking lots of fluids are important in treating symptoms and feeling better for people with mild cases of COVID-19. If you suspect COVID-19, monitor the progression of your symptoms and keep your doctor updated about your symptoms.

Your doctor will recommend additional at-home treatment plans, which may include over-the-counter medication, oxygen monitoring devices, or prescription medication, like an inhaler. They may recommend getting an experimental antibody infusion if you are at high risk of complications. They can also advise you when to go to the hospital if your symptoms worsen.

4. Acid reflux disease and gastritis


  • Burning sensation in the middle of your chest or upper abdomen, usually after eating or when lying down
  • Acidic taste

Acid reflux is when acid from the stomach goes into your esophagus causing burning pain (heartburn) in your chest. If acid reflux happens more than twice a week, it's considered GERD (gastroesophageal reflux disease). It often occurs if you eat or drink certain foods such as alcohol or spicy, fried, fatty, and/or acidic foods including chocolate or coffee.

Gastritis is inflammation of the stomach lining most often caused by an infection from H. pylori or from overuse of alcohol or non-steroidal anti-inflammatory drugs (NSAIDs). Pain usually occurs when acid enters the stomach after eating and further irritates the stomach lining. If not properly treated, this may lead to ulcers.

The best treatment is to change your diet or avoid foods that trigger your symptoms. Other lifestyle changes include eating smaller, more frequent meals, staying upright after eating, and losing weight.

If these treatments do not improve your symptoms, your doctor may recommend testing for H. pylori, starting medications, or you may need a procedure called an endoscopy to look at the inner lining of your esophagus and stomach.

If the nausea is from too much acid, then anti-acid medications, such as famotidine (Pepcid) may help. Other medications include those that coat the stomach (like Maalox) or that absorb the acid in the stomach (like TUMS).

If you have an H. pylori infection, you will need antibiotics.

5. Indigestion (dyspepsia)


Symptoms of indigestion, also known as dyspepsia, include pain, discomfort, and bloating in the upper abdomen soon after eating. It’s often from eating too much or too quickly, eating greasy or spicy foods, or drinking too much caffeine, alcohol, or carbonated drinks. Smoking, anxiety, and certain medications can also cause indigestion.

Treatment includes avoiding triggers and eating smaller meals, more often. If the indigestion lasts longer than 2 weeks and doesn’t improve after you’ve changed your eating habits, see a doctor.

6. Morning sickness


  • Nausea or vomiting
  • Pregnancy

Many women experience nausea and vomiting when they’re pregnant, especially in the first trimester. Even though it’s called morning sickness, it can happen any time of the day.

It is helpful to avoid an empty stomach. Try eating bland food like crackers immediately after waking up in the morning and throughout the day. Eat a high protein food before going to bed.

If you continue to have symptoms or develop signs of dehydration, you can ask your doctor about over-the-counter options such as ginger, vitamin B-6 supplements, and doxylamine (Unisom). Your doctor may prescribe anti-nausea medications.

Some women find acupuncture, acupressure, and aromatherapy helpful. But it is important to discuss any treatments with your doctor first to make sure they are safe for you and your baby.

7. Bowel obstruction


Two common bowel obstructions include small bowel obstruction and gastric outlet obstruction. It is a medical emergency regardless of the cause.

The small intestine is a long, coiled, tube-like structure that connects the stomach to the large intestine (colon). If something blocks the small intestine, food and liquid can’t pass through.

The most common cause is scar tissue, either from a previous surgery, inflammation, or infections. Certain conditions like Crohn’s disease or diverticulitis create inflammation that can cause the intestinal wall to thicken and narrow. A hernia or tumor can also cause a physical blockage.

Gastric outlet obstruction is from a mass that blocks the stomach. Since nothing, including swallowed saliva and water, can pass, you may have clear vomit. But you will also vomit anything that you try to eat.

Go to the hospital as the blockage will need to be treated immediately—usually with surgery.

8. Motion sickness


  • Nausea or vomiting
  • Dizziness or feeling uneasy
  • Cold sweats

Motion sickness is brought on by movement, usually a car, bus, train, plane, or a boat. It happens when your brain receives mixed signals or interprets signals incorrectly.

Your brain uses your vision, inner ears, and body position to monitor balance. Your eyes tell you if you are upright. Your inner ears sense if you are tilted or turning. And your nerves sense your body’s position. During motion sickness, at least one of these senses is misinterpreted by the brain and you feel like you are spinning, falling, or moving. Then you become nauseated.

The best treatment is to stop the motion. If this is not possible, then help your brain interpret these signals correctly. Try staring at a non-moving object or finding something else to focus on help. In a car, avoid reading, looking at screens, and sit in the front seat. On a boat, look at the horizon rather down at the water, or go to the upper decks.

If you know you are at risk of motion sickness, you can take medications ahead of time. Medications work best when taken one to a few hours before. Sometimes, you will have to take repeat doses.  Medications include antihistamines such as Dramamine, scopolamine, and meclizine (Antivert). Some people also get relief with acupressure.

9. Medications


  • Nausea
  • Increase salivation
  • Side effects of specific medication

Many medications include nausea as a potential side effect.

In particular, chemotherapy treatments for cancer can cause nausea. These medications can trigger the vomiting centers of the brain. They also may damage your digestive tract, which can lead to nausea and vomiting. Your oncologist (cancer doctor) should know which chemotherapy treatment is most likely to cause these symptoms and will give you anti-nausea medications to prevent and treat nausea.

Anesthesia used in surgery can also cause nausea. If you know you are likely to suffer from nausea and vomiting after surgery, you may be given anti-nausea medications before the surgery to prevent it.

Other medications that may cause nausea are antibiotics, some vitamins and supplements, and pain relievers, including nonsteroidal antiinflammatory medications (NSAIDs) and opioid pain medications. Sometimes, not taking these medications on an empty stomach will keep you from getting nauseated.

If the nausea continues, call your doctor, who may need to change your medication.

10. Toxins


Symptoms depend on the toxin.

  • Alcohol intoxication: nausea, unsteady gait, slurred speech, confusion
  • Hangover from alcohol: nausea, dizziness, headache, upper belly pain
  • Drug use:
    • Marijuana and synthetic cannabinoids (K-2): nausea, red eyes, nystagmus (eyes involuntarily moving rapidly from side to side), difficulty concentrating, paranoia
    • Opiates: nausea, euphoria, drowsiness, slowed breathing, itching
    • PCP: nausea, delusions, paranoia, nystagmus (eyes involuntarily moving rapidly from side to side), dizziness, seizure
    • Synthetic cathinones (bath salts): nausea, euphoria, paranoia, dizziness, sweating, confusion
    • Opiate withdrawal: nausea, goosebumps, diarrhea, insomnia, belly cramps, muscle aches

There are many toxins that can cause nausea. It is usually from a side effect of a toxin or because the toxin leads to acute gastritis—like from too much alcohol. Just like with infections, nausea with vomiting can be your body’s way of getting rid of toxins.

Cannabinoid hyperemesis syndrome (CHS) can be from long-term cannabis use. It causes repeated bouts of nausea, vomiting, and abdominal cramping. Taking hot showers or baths can help. So can over-the-counter capsaicin cream.

Treatment is to stop using cannabis. However, if your symptoms are severe, you may need to go to the ER to get anti-nausea medications and possibly intravenous (IV) fluids.

11. Vertigo

What does nausea feel like?

“Unfortunately, nausea can feel miserable. Luckily, it is not usually dangerous or life threatening.” —Dr. Manuelpillai


Vertigo is the sensation of spinning. It can be caused by a central process (i.e., the brain) or a peripheral process (most commonly the ears). It can also be a side effect of certain medical problems, medications, drugs, or alcohol.

It can be caused by ear infections or fluid buildup or calcification in inner ear canals. Treatment depends on the cause but can include medications such as meclizine, movements that reposition calcifications in the ear canal, surgery, or physical therapy such as vestibular rehabilitation.

Vertigo may also be caused by more serious brain bleeds, brain tumors, or strokes.

12. Brain/head injury


Nausea and vomiting can be a serious sign of a brain injury. It can occur with minor head trauma such as concussions, but also with brain damage or bleeding.

Severe or worsening vomiting may be from an injury that causes bleeding or swelling and increasing pressure in the skull. This can be life-threatening. If you have any of these symptoms, go directly to an ER for an urgent evaluation.

13. Migraines


  • Nausea and vomiting
  • Sensitivity to light and sound
  • Sometimes sensitivity to certain smells or tastes
  • Throbbing usually unilateral (one sided) headache

A migraine is a type of recurring, severe headache. It may start with an aura—visual symptoms that occur before the headache hits. These can include seeing lines or flashing lights.

Treatment involves taking medications at the first sign of symptoms and avoiding potential triggers like bright lights. If you have an aura, take medication as soon as it starts.

You may be able to treat migraines with over-the-counter medications. But if your migraines become severe or frequent, you may need a prescription medication for when the migraine occurs, and preventative medications or treatments to reduce the frequency of migraines.

14. Stroke


  • Nausea and/or vomiting
  • Sometimes headache
  • Can vary depending on type, but commonly include facial droop, slurred speech, trouble walking, and weakness and/or numbness

Strokes occur when an area of the brain stops receiving its blood supply.

A stroke is a medical emergency.  You need to get treated immediately. If you think you’ve had a stroke, call 911 and go to the ER as soon as possible. You will be treated more quickly if you call 911—as opposed to a family member taking you to the hospital. This time-saving can be life-saving.

There are two types of strokes—strokes from a bleed (hemorrhagic) and strokes from a clot (ischemic).

Hemorrhagic strokes are often caused by uncontrolled high blood pressure. Ischemic strokes are more likely if you have an abnormal rhythm (atrial fibrillation) or medical problems that can increase your risk of artherosclerotic disease such as high blood pressure, diabetes, and smoking.

Nausea and vomiting from a stroke can be from increased pressure in the brain or if the affected area includes the vomiting centers of the brain or the parts responsible for balance.

15. Brain tumor or lesion


A brain tumor or lesion may be due to cancer, an infection, calcifications, or malformation of blood vessels. Nausea and vomiting are from increased pressure in the brain or because of the area of the brain being affected.

Treatment depends on the type of the tumor or lesion. Many cause minimal-to-no symptoms or are not dangerous. If you have an infection, treatment is usually aggressive antibiotic treatment, but you may also need to have a drain inserted. If you are diagnosed with cancer, treatment may include chemotherapy, radiation, and or surgery.

Other possible causes

A number of conditions, like gallbladder disease and a heart attack, may also cause nausea. During a heart attack, some people, especially the elderly and those with diabetes, may only have vague complaints such as nausea, dizziness, or fatigue.

When to call the doctor

How do I get rid of nausea?

“Discuss with your doctor whether your nausea is something to be concerned about and how you can manage it at home whether with medication or other interventions.” —Dr. Manuelpillai

You should see your doctor if:

  • Your nausea has come and gone for more than a month
  • You have unexplained weight loss
  • You've been vomiting for more than 2 days

Should I go to the ER for nausea and vomiting?

Seek immediate treatment in the emergency room if:

  • You're experiencing chest pain, palpitations, severe abdominal pain, or you have an intense headache
  • You're confused, have dizziness, or are having trouble seeing
  • You have a high fever and/or stiff neck
  • You have rectal bleeding
  • You have blood (either bright red or coffee ground) in your vomit
  • You have been nauseated or vomiting for more than 2 days and are not able to eat or drink any food or liquid
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At-home care

  • Over-the-counter anti-nausea medications include Pepto-Bismol, Meclizine (Antivert), and Dramamine
  • Fresh ginger tea often helps calm nausea
  • Vitamin B6 supplements may help
  • Peppermint oil, which you can mix with coconut oil and rub directly beneath your nose, may help relax your stomach
  • Acupressure may help prevent and treat nausea

Other treatment options

Your doctor may also prescribe anti-nausea medications for more severe nausea.

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Once your story receives approval from our editors, it will exist on Buoy as a helpful resource for others who may experience something similar.
The stories shared below are not written by Buoy employees. Buoy does not endorse any of the information in these stories. Whenever you have questions or concerns about a medical condition, you should always contact your doctor or a healthcare provider.
Dr. Le obtained his MD from Harvard Medical School and his BA from Harvard College. Before Buoy, his research focused on glioblastoma, a deadly form of brain cancer. Outside of work, Dr. Le enjoys cooking and struggling to run up-and-down the floor in an adult basketball league.

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