Cyclic vomiting syndrome (1330)

Key points below

What is cyclic vomiting syndrome?

Cyclic vomiting syndrome (CVS) is a condition that involves repeated vomiting episodes. The episodes can be predictable since they often start at the same time of day, last the same length of time. They have the same severity of symptoms. There are 4 phases of CVS (see the picture below.) CVS episodes can range in severity. They can last from several hours to a few days. It affects people of any age. It usually starts in children 3 to 7 years old.

What causes cyclic vomiting syndrome?

There are no known causes for CVS. Researchers believe the problem starts in the brain. The body’s vomiting center is in the brain. Studies have shown that CVS is often linked to a family history of migraine headaches. Many children may have fewer vomiting episodes at some point. They may outgrow CVS. CVS can lead to abdominal migraines or migraine headaches later in life.

What are the triggers?

The most common triggers are:

What are the symptoms?

What tests might need to be done?

CVS is diagnosed by your child’s symptom pattern. Based your child’s symptoms, their health care provider may order other tests to rule out other conditions.

How is it treated?

There is no cure for CVS. There are ways to help prevent or reduce your child’s symptoms. Things you can do may include:

When to seek help?

Talk to your child’s health care provider if:

cyclic phases chart


CVS may lead to dehydration. This can cause serious health problems. Call your provider right away if your child is showing any of the following:

  • No wet diaper or peeing for 8 to 10 hours
  • No tears when crying, sunken eyes, or a dry mouth
  • More sleepy, restless, or crabby than normal
  • Large amount of blood in vomit or stool