Cyclic vomiting syndrome is characterized by episodes of severe vomiting that have no apparent cause. Episodes can last for hours or days and alternate with symptom-free periods. Episodes are similar, meaning that they tend to start at the same time of day, last the same length of time, and occur with the same symptoms and intensity.

Cyclic vomiting syndrome occurs in all age groups, though it often begins in children around 3 to 7 years old. Although it's more common in children, the number of cases diagnosed in adults is increasing.

The syndrome is difficult to diagnose because vomiting is a symptom of many disorders. Treatment often involves lifestyle changes to help prevent the events that can trigger vomiting episodes. Medications, including anti-nausea and migraine therapies, may help lessen symptoms.


The symptoms of cyclic vomiting syndrome often begin in the morning. Signs and symptoms include:

  • Three or more recurrent episodes of vomiting that start around the same time and last for a similar length of time
  • Varying intervals of generally normal health without nausea between episodes
  • Intense nausea and sweating before an episode starts

Other signs and symptoms during a vomiting episode may include:

  • Abdominal pain
  • Diarrhea
  • Dizziness
  • Sensitivity to light
  • Headache
  • Retching or gagging

When to see a doctor

Call your doctor if you see blood in your or your child's vomit.

Continued vomiting may cause severe dehydration that can be life-threatening. Call your doctor if you or your child is showing symptoms of dehydration, such as:

  • Excess thirst or dry mouth
  • Less urination
  • Dry skin
  • Sunken eyes or cheeks
  • No tears when crying
  • Exhaustion and listlessness


The underlying cause of cyclic vomiting syndrome is unknown. Some possible causes include genes, digestive difficulties, nervous system problems and hormone imbalances. Specific bouts of vomiting may be triggered by:

  • Colds, allergies or sinus problems
  • Emotional stress or excitement, especially in children
  • Anxiety or panic attacks, especially in adults
  • Certain foods and drinks, such as alcohol, caffeine, chocolate or cheese
  • Overeating, eating right before going to bed or fasting
  • Hot weather
  • Physical exhaustion
  • Exercising too much
  • Menstruation
  • Motion sickness

Identifying the triggers for vomiting episodes may help with managing cyclic vomiting syndrome.

Risk factors

The relationship between migraines and cyclic vomiting syndrome isn't clear. But many children with cyclic vomiting syndrome have a family history of migraines or have migraines themselves when they get older. In adults, cyclic vomiting syndrome is also associated with a personal or family history of migraines.

Chronic use of marijuana (Cannabis sativa) also has been associated with cyclic vomiting syndrome because some people use marijuana to relieve their nausea. However, chronic marijuana use can lead to a condition called cannabis hyperemesis syndrome, which typically leads to persistent vomiting without normal intervening periods. People with this syndrome often demonstrate frequent showering or bathing behavior.

Cannabis hyperemesis syndrome can be confused with cyclic vomiting syndrome. To rule out cannabis hyperemesis syndrome, you need to stop using marijuana for at least one to two weeks to see if vomiting lessens. If it doesn't, your doctor will continue testing for cyclic vomiting syndrome.


Cyclic vomiting syndrome can cause these complications:

  • Dehydration. Excessive vomiting causes the body to lose water quickly. Severe cases of dehydration may need to be treated in the hospital.
  • Injury to the food tube. The stomach acid that comes up with the vomit can damage the tube that connects the mouth and stomach (esophagus). Sometimes the esophagus becomes so irritated it bleeds.
  • Tooth decay. The acid in vomit can corrode tooth enamel.


Many people know what triggers their cyclic vomiting episodes. Avoiding those triggers can reduce the frequency of episodes. While you may feel well between episodes, it's very important to take medications as prescribed by your doctor.

If episodes occur more than once a month or require hospitalization, your doctor may recommend preventive medicine, such as amitriptyline, propranolol (Inderal), cyproheptadine and topiramate.

Lifestyle changes also may help, including:

  • Getting adequate sleep
  • For children, downplaying the importance of upcoming events because excitement can be a trigger
  • Avoiding trigger foods, such as alcohol, caffeine, cheese and chocolate
  • Eating small meals and low-fat snacks daily at regular times

Jul 10, 2021

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  3. Li BU. Cyclic vomiting syndrome. https://www.uptodate.com/contents/search. Accessed April 13, 2021.
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  5. Cyclic vomiting syndrome. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/digestive-diseases/cyclic-vomiting-syndrome. Accessed April 12, 2021.
  6. Raucci U, et al. Cyclic vomiting syndrome in children. Frontiers in Neurology. 2020; doi:10.3389/fneur.2020.583425.


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