Cyclic vomiting syndrome is a disorder that causes recurrent episodes of nausea, vomiting, and tiredness (lethargy). This condition is diagnosed most often in young children, but it can affect people of any age.
Cyclic vomiting syndrome is characterized by attacks of intense nausea, vomiting, and lethargy that last anywhere from an hour to 10 days. An affected person may vomit several times per hour, potentially leading to a dangerous loss of fluids (dehydration). Additional symptoms can include unusually pale skin (pallor), abdominal pain, diarrhea, headache, and an increased sensitivity to light (photophobia) or to sound (phonophobia). In most affected people, the signs and symptoms of each attack are quite similar. These attacks can be debilitating, making it difficult for an affected person to go to work or school.
Episodes of nausea and vomiting can be triggered by several different factors. The most common triggers are emotional excitement and infections. Other triggers can include periods without eating (fasting), temperature extremes, lack of sleep, overexertion, allergies, ingesting certain foods or alcohol, and menstruation.
If the condition is not treated, attacks typically occur four to 12 times per year. Between episodes, vomiting is absent, and nausea is either absent or much reduced. However, many affected people experience other symptoms during and between episodes, including pain, digestive disorders such as gastroesophageal reflux and irritable bowel syndrome, and fainting spells (syncope). People with cyclic vomiting syndrome are also more likely than people without the disorder to experience depression, anxiety, and panic disorder. It is unclear how these health conditions are related to nausea and vomiting.
Cyclic vomiting syndrome is generally considered to be a variant of migraines, which are severe headaches often associated with pain, nausea, vomiting, and extreme sensitivity to light and sound. Many people with cyclic vomiting syndrome have a family history of migraines, and attacks of nausea and vomiting may be replaced by migraine headaches as an affected person gets older.
Most people with cyclic vomiting syndrome have normal intelligence, although some affected people have experienced developmental delay or intellectual disability, muscle weakness (myopathy), and/or seizures. People with these additional features are said to have cyclic vomiting syndrome plus.