Cyclic Vomiting Syndrome

Cyclic vomiting syndrome is when you experience cycles of severe nausea, vomiting and exhaustion that can last from a few hours up to a few days. Although the symptoms won’t occur daily, the syndrome can last a lifetime. Avoiding triggers and taking anti-seizure and anti-nausea medications can help.


What is cyclic vomiting syndrome (CVS)?

Cyclic vomiting syndrome (CVS) involves repeated, unexplained episodes of severe nausea and vomiting. Episodes can last from a few hours to several days. They can be so severe that you need to stay in bed. You may need to go to the emergency room (ER) or hospital to get IV fluids to prevent dehydration. Following an episode, you’re free of symptoms and return to normal health.

CVS may last for months, years or decades. However, symptoms don’t occur every day. Episodes generally occur several times a year but can happen up to once or twice a month.

The symptoms, time of day, frequency, severity and length of each episode are usually the same for any one person. But these factors can vary from person to person.

How common is cyclic vomiting syndrome?

CVS is more common in children than adults. Approximately 3 of every 100,000 children have CVS. In most cases in children, episodes start between the ages of 3 and 7. However, the disorder can begin at any age.


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Symptoms and Causes

What are the symptoms of cyclic vomiting syndrome (CVS)?

Cyclic vomiting syndrome (CVS) involves sudden, repeated episodes of severe nausea and vomiting. Episodes often unfold like this:

  • Prodrome phase: You start feeling nauseated and sweaty in the minutes or hours leading up to the vomiting. For most people, the feeling starts in the early morning hours.
  • Vomiting phase: You vomit, sometimes several times an hour. Children with CVS may projectile vomit. The vomiting may last for a few hours or even a few days. The experience can feel so intense that you’re unable to talk to others and need to stay in bed alone.
  • Recovery phase: The vomiting and nausea gradually improve.
  • Well phase: You return to feeling like yourself again.

Other signs and symptoms of CVS include:

What causes cyclic vomiting syndrome (CVS)?

There isn’t a single known cause of CVS. Instead, several factors may play a role, including:

  • Issues with your brain-gut axis. Problems with how your brain communicates with nerves in your gastrointestinal (GI) tract may lead to uncontrollable vomiting. Some scientists call CVS a brain-gut disorder.
  • Changes or imbalances in your autonomic nervous system. Your autonomic nervous system controls involuntary activities, like your heartbeat, blood pressure and vomiting reflex. A glitch in the system can lead to vomiting episodes.
  • Migraine headaches. Migraine headaches appear in up to 80% of children and 25% of adults with CVS. A migraine is significantly more intense than just a bad headache. Like CVS, it usually begins with an uncomfortable feeling that an episode is about to start. Many people with CVS have a family history of migraines.
  • Abnormal mitochondrial DNA. Mitochondria power cells. The instructions that tell mitochondria how to work (DNA) can become abnormal because of an illness, a genetic condition or exposure to drugs or toxins. The nerve cells in your gut require a lot of energy to work correctly. Problems with their power source (mitochondria) may cause uncontrollable vomiting.


What triggers cyclic vomiting syndrome (CVS)?

Certain conditions, events and emotional states can trigger a vomiting episode, including:

  • Seasonal changes (symptoms are more common in fall and winter).
  • Reactions to foods like chocolate, cheese, caffeine or MSG.
  • Heightened positive emotions, like excitement (in children).
  • Panic attacks, stress and anxiety (in adults).
  • Allergies, sinus infections or the flu.
  • Physical exhaustion.
  • Prolonged fasting.
  • Prolonged marijuana use.
  • Menstrual periods.
  • Motion sickness.

What complications can result from cyclic vomiting syndrome (CVS)?

CVS can lead to:

  • Dehydration: Vomiting and diarrhea can cause you to lose too much fluid.
  • Esophagitis: The vomit (which is acidic) can cause inflammation in your esophagus.
  • Mallory-Weiss tear: Severe muscular contractions from the vomiting can tear the lower end of your esophagus.
  • Tooth decay: The vomit can wear away your tooth enamel and cause cavities.


Diagnosis and Tests

How is cyclic vomiting syndrome (CVS) diagnosed?

Diagnosing CVS involves ruling out other conditions that cause similar symptoms. Your healthcare provider will ask questions about your medical history, family medical history, and your pattern of vomiting and nausea.

You’ll need a physical exam and (likely) several tests.

What tests do providers use to diagnose CVS?

There isn’t a single test to diagnose CVS. Instead, your provider may order several tests to exclude other conditions that cause vomiting. Tests include:

  • Lab tests (blood and urine tests): Lab tests check body fluids for signs of metabolic disorders, mitochondrial disease or problems with your organs that can cause CVS symptoms.
  • Imaging tests: Imaging tests can reveal issues with organs in your digestive and nervous systems that cause vomiting. You may need an abdominal ultrasound, a brain MRI (magnetic resonance imaging), CT scan (computed tomography scan) or X-rays called an upper GI series. You may need a gastric emptying test to see how food moves through your digestive system.
  • Upper endoscopy: This test can show problems in your esophagus, stomach or small intestine that may be causing your vomiting episodes.

What conditions can be mistaken for cyclic vomiting syndrome?

A CVS diagnosis involves ruling out common conditions that cause vomiting, including infections, acid reflux (GERD) and stomach ulcers. Your provider may also need to exclude:

Management and Treatment

How is cyclic vomiting syndrome (CVS) treated?

Treatment for cyclic vomiting syndrome depends on whether you’re experiencing an episode or trying to prevent one from happening.

  • Prodrome phase (symptom onset): When symptoms first start, healthcare providers use medications to manage nausea, reduce stomach acid and relieve migraine symptoms and abdominal pain.
  • Vomiting phase: Providers prescribe medicines to manage migraines and reduce your stomach acid and anxiety. You may need to go to a hospital to receive IV fluids and nutrition to prevent dehydration. It’s a good idea to rest in a dark and quiet environment. Calming environments can ease symptoms.
  • Recovery phase: You’ll continue to receive IV fluids as needed. You may progress gradually to clear liquids first and then solid foods. Or, you may feel ready for solid foods immediately after the vomiting stops.
  • Well phase: You may receive medications to prevent future episodes. You’ll likely need a trial period to test how effective a treatment is.

What medications treat CVS?

Medications stop an episode, reduce its intensity or prevent it from happening. Your prescription depends on your age, how severe your episodes are and how you’ve responded to other forms of treatment.

Medications include:

You may also benefit from taking supplements, including coenzyme Q10, riboflavin and L-carnitine at doses recommended by your provider. Never start a supplement without getting your provider’s OK first.


Tips for reducing your risk of a cyclic vomiting syndrome (CVS) episode
Recognizing and avoiding triggers can reduce your risk of a CVS episode.

How can cyclic vomiting syndrome (CVS) be prevented?

You can reduce your risk of an episode by avoiding triggers and taking medications as prescribed by your healthcare provider. Other tips include:

  • Treat allergies and sinus problems immediately.
  • Stay active, but don’t over-exercise.
  • Avoid food and food additive triggers.
  • Avoid extreme diets or fasting.
  • Get the right amount of sleep.
  • Manage stress and anxiety.

Outlook / Prognosis

What can I expect if I have CVS?

Many children with CVS eventually outgrow it but develop severe migraines as adults. Persistent and severe vomiting can disrupt daily life for children and adults alike. Children may have to miss school, and adults may have to miss work. Depending on how severe the vomiting is, you may need to be hospitalized to prevent dehydration.

Working with your provider to find the right treatments and identify your triggers is essential. Everyone’s experience is different. It’s important to find what works for you.

Living With

What questions should I ask my healthcare provider?

Ask your provider:

  • What tests will I need to determine whether I have CVS?
  • What medicines will I need to stop or prevent an episode?
  • What lifestyle changes can I make to avoid my triggers?
  • What lifestyle changes can I make to improve my symptoms?
  • When should I contact you or visit the ER when I’m experiencing CVS symptoms?

A note from Cleveland Clinic

CVS may feel as if your gut (and vomiting reflex) has turned against you. It’s a frustrating diagnosis, especially since no single medicine or lifestyle change guarantees you won’t have an episode. Be patient with yourself and your provider as you find treatments that work. It may take some time to identify your triggers, but eventually, most people with CVS get good at learning and avoiding them. In the meantime, some medicines can ease your symptoms when an episode does start.

Medically Reviewed

Last reviewed on 11/02/2023.

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