Cyclic Vomiting Syndrome

Cyclic Vomiting Syndrome: Overview

Alternative names: CVS, Cyclical Vomiting, Childhood/Adult Cyclic Vomiting, Abdominal Migraine

Cyclic Vomiting Syndrome (CVS) is a disorder characterized by repeated episodes of nausea and vomiting that last for hours to days separated by symptom-free periods of variable length.  In adults, the disorder has been described as consisting of episodes of nausea and vomiting lasting for three to six days in a patient-specific pattern.

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Medical researchers consider Cyclic Vomiting Syndrome to be a variant of migraines, and indeed many children who suffer from CVS also suffer from migraines as adults.

Incidence; Causes and Development; Contributing Risk Factors

The prevalence of CVS is not accurately known, with estimates for children ranging from 3.15 to 2,000 cases per 100,000.  CVS most commonly occurs in children between the ages of 3 and 7, with girls being 20-25% more likely to be affected than boys.

Although it is predominantly diagnosed in children, adults can also be affected.

Although the precise cause of Cyclic Vomiting Syndrome is not known, it is believed that several factors can contribute to the disorder, including:

  • Brain function disorder
  • Hormonal abnormalities
  • Gastrointestinal problems
  • Changes in mitochondrial DNA
  • Anxiety or emotional stress
  • Physical exhaustion
  • Depression
  • Sleep deprivation
  • Motion Sickness
  • Infections such as sinus infections or respiratory infections
  • Overeating or fasting
  • MSG-containing foods
  • Cheese, chocolate or cured meats
  • Caffeine
  • Alcohol
  • Hot weather
  • Menstruation

Many individuals with Cyclic Vomiting Syndrome have a family history of conditions that are related to CVS, such as migraines or light sensitivity.  Researchers in one study found that 86% of children affected by CVS had mothers with a history of migraines.

Signs and Symptoms

The hallmark of Cyclic Vomiting Syndrome is the pattern of alternating symptom-free periods followed by periods of vomiting.  The symptoms can be divided into 4 phases that can be used to diagnose CVS, as follows:

  • Phase 1 – The Interval phase. This refers to the period between vomiting episodes where no symptoms are present.
  • Phase 2 – The Prodromal phase. This phase is characterized by nausea and is the first indication that vomiting is about to begin.  Nausea can last for a few minutes or up to several hours.  Taking prescribed medicine during this phase can sometimes prevent an episode.
  • Phase 3 – The Vomiting phase. Vomiting begins and causes an inability to drink or eat anything.  It is also accompanied by paleness, drowsiness and exhaustion.  Vomiting can take place 5 to 6 times an hour, and last for up to 10 days.  This phase is often also accompanied by abdominal pain, diarrhea, fever and headaches.
  • Phase 4 – The Recovery phase. Nausea and vomiting cease, followed by the return of appetite and energy.

The recurrent episodes are similar each time and often begin at the same time of day with a severity and duration that matches the previous episodes.  Whereas with most gastrointestinal disorders vomiting will relieve the nausea, this is not the case in Cyclic Vomiting Syndrome.  In some cases vomiting can be so severe that the affected individual is unable to talk and may even appear to be unconscious.

Additional symptoms may include:

  • Pale skin
  • Lethargy
  • Abdominal pain
  • Fever
  • Drooling
  • Diarrhea
  • Headaches
  • Increased sensitivity to light

Diagnosis and Tests

The alternating pattern of vomiting followed by symptom-free periods is what distinguishes Cyclic Vomiting Syndrome from other gastrointestinal disorders.

There are no tests to diagnose CVS so doctors must rely on family medical history, physical examination, and observable patterns of symptoms to make a proper diagnosis.  To identify these patterns – or cycles – of symptoms can take a long time.  Certain medical tests can be used to exclude the possibility of other conditions that might bring about cyclic vomiting symptoms.

In cases where a doctor suspects that a child is affected by cyclic vomiting syndrome, he may ask questions such as the following:

  • Did the child experience two or more continuous episodes of nausea and vomiting lasting for days within a 6-month timeframe?
  • Were these episodes similar each time?
  • Were the episodes separated by weeks or months of normal health?
  • Can the symptoms possibly be attributed to any other disorder that causes vomiting?

Cyclic Vomiting Syndrome can be diagnosed in adults if they have experienced three or more vomiting episodes within the past twelve months with periods of no vomiting or nausea in between these episodes.

Treatment and Prevention

Medicine can be prescribed to prevent episodes of CVS or reduce their frequency, but the type of treatment depends on the phase.  Migraine medicines have been proven to help with the treatment of CVS.

Individuals suffering from CVS should get enough rest and avoid triggers of the disorder.  During Phase 2 (the Prodromal phase), an oncoming episode can be stopped: Ondansetron (Zofran) or lorazepam (Ativan) for nausea and/or ibuprofen (Advil) for pain.

During Phase 3 (the Vomiting phase) it is important that the individual stay in bed in a dark and quiet environment.  Severe nausea and vomiting might cause dehydration and therefore intravenous fluids should be given if the individual is hospitalized.  Sedatives can also be prescribed if the nausea continues.

Treatment during Phase 4 (the Recovery phase) includes drinking a lot of water and replacing electrolytes that have been lost.  Care should be taken not to immediately start eating once appetite returns to normal: begin by drinking liquids and then slowly introduce more solid food.  Migraine medication such as propranolol (Inderal), cyproheptadine (Periactin), and amitriptyline (Elavil) can be used during this phase to prevent further symptoms.

During Phase 1 (the Interval or symptom-free phase) it is important to reduce and remove all known triggers of CVS.  If stress or excitement are known to bring on episodes, it is important to look at ways to reduce stress by making use of behavioral therapy.


Complications that may arise from cyclic vomiting syndrome include:

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