Cyclic Vomiting Syndrome Fact Book
In cyclic vomiting syndrome (CVS), people experience bouts or cycles of
severe nausea and vomiting that last for hours or even days and alternate
with longer periods of no symptoms. CVS occurs mostly in children, but the
disorder can affect adults, too.
CVS has no known cause. Each episode is similar to the previous ones.
The episodes tend to start at about the same time of day, last the same
length of time, and present the same symptoms at the same level of
intensity. Although CVS can begin at any age in children and adults, it
usually starts between the ages of 3 and 7. In adults, episodes tend to
occur less often than they do in children, but they last longer.
Furthermore, the events or situations that trigger episodes in adults
cannot always be pinpointed as easily as they can in children.
Episodes can be so severe that a person may have to stay in bed for
days, unable to go to school or work. No one knows for sure how many
people have CVS, but medical researchers believe that more people may have
the disorder than is commonly thought (as many as 1 in 50 children in one
study). Because other more common diseases and disorders also cause cycles
of vomiting, many people with CVS are initially misdiagnosed until the
other disorders can be ruled out. What is known is that CVS can be
disruptive and frightening not just to people who have it, but to the
entire family as well.
CVS has four phases:
- Symptom-free interval
The prodrome phase signals that an episode of nausea and
vomiting is about to begin. This phase, which is often marked by abdominal
pain, can last from just a few minutes to several hours. Sometimes taking
medicine early in the prodrome phase can stop an episode in progress.
However, sometimes there is no warning: A person may simply wake up in the
morning and begin vomiting.
The episode phase consists of nausea and vomiting; inability to
eat, drink, or take medicines without vomiting; paleness; drowsiness; and
The recovery phase begins when the nausea and vomiting stop.
Healthy color, appetite, and energy return.
The symptom-free interval phase is the period between episodes
when no symptoms are present.
Most people can identify a specific condition or event that triggered
an episode. The most common trigger is an infection. Another, often found
in children, is emotional stress or excitement, often from a birthday or
vacation, for example. Colds, allergies, sinus problems, and the flu can
also set off episodes in some people.
Other reported triggers include eating certain foods (such as chocolate
or cheese), eating too much, or eating just before going to bed. Hot
weather, physical exhaustion, menstruation, and motion sickness can also
The main symptoms of CVS are severe vomiting, nausea, and retching
(gagging). Episodes usually begin at night or first thing in the morning
and may include vomiting or retching up to five or six times an hour
during the worst of the episode. Episodes usually last anywhere from 1 to
4 days, though they can last for up to 10 days.
Other symptoms include pallor, exhaustion, and listlessness. Sometimes
the nausea and vomiting are so severe that a person appears to be almost
unconscious. Sensitivity to light, headache, fever, dizziness, diarrhea,
and abdominal pain may also accompany an episode.
In addition, the vomiting may cause drooling and excessive thirst.
Drinking water usually leads to more vomiting, though the water can dilute
the acid in the vomit, making the episode a little less painful.
Continuous vomiting can lead to dehydration, which means that the body has
lost excessive water and salts.
CVS is hard to diagnose because no clear tests--such as a blood test or
x ray--exist to identify it. A doctor must diagnose CVS by looking at
symptoms and medical history and by excluding more common diseases or
disorders that can also cause nausea and vomiting. Also, diagnosis takes
time because doctors need to identify a pattern or cycle to the
The relationship between
migraine and CVS is still unclear, but medical researchers believe
that the two are related. First, migraine headaches, which cause
severe pain in the head; abdominal migraine, which causes stomach
pain; and CVS are all marked by severe symptoms that start quickly
and end abruptly, followed by longer periods without pain or other
Second, many of the situations that trigger CVS also trigger
migraines. Those triggers include stress and excitement.
Third, research has shown that many children with CVS either have
a family history of migraine or develop migraines as they grow
Because of the similarities between migraine and CVS, doctors
treat some people with severe CVS with drugs that are also used for
migraine headaches. The drugs are designed to prevent episodes,
reduce their frequency, or lessen their
CVS cannot be cured. Treatment varies, but people with CVS are
generally advised to get plenty of rest; sleep; and take medications that
prevent a vomiting episode, stop or alleviate one that has already
started, or relieve other symptoms.
Once a vomiting episode begins, treatment is supportive. It helps to
stay in bed and sleep in a dark, quiet room. Severe nausea and vomiting
may require hospitalization and intravenous fluids to prevent dehydration.
Sedatives may help if the nausea continues.
Sometimes, during the prodrome phase, it is possible to stop an episode
from happening altogether. For example, people who feel abdominal pain
before an episode can ask their doctor about taking ibuprofen (Advil,
Motrin) to try to stop it. Other medications that may be helpful are
ranitidine (Zantac) or omeprazole (Prilosec), which help calm the stomach
by lowering the amount of acid it makes.
During the recovery phase, drinking water and replacing lost
electrolytes are very important. Electrolytes are salts that the body
needs to function well and stay healthy. Symptoms during the recovery
phase can vary: Some people find that their appetites return to normal
immediately, while others need to begin by drinking clear liquids and then
move slowly to solid food.
People whose episodes are frequent and long-lasting may be treated
during the symptom-free intervals in an effort to prevent or ease future
episodes. Medications that help people with migraine
headaches--propranolol, cyproheptadine, and amitriptyline--are sometimes
used during this phase, but they do not work for everyone. Taking the
medicine daily for 1 to 2 months may be necessary to see if it helps.
In addition, the symptom-free phase is a good time to eliminate
anything known to trigger an episode. For example, if episodes are brought
on by stress or excitement, this period is the time to find ways to reduce
stress and stay calm. If sinus problems or allergies cause episodes, those
conditions should be treated.
The severe vomiting that defines CVS is a risk factor for several
- Dehydration. Vomiting causes the body to lose water
- Electrolyte imbalance. Vomiting also causes the body to lose
the important salts it needs to keep working properly.
- Peptic esophagitis. The esophagus (the tube that connects the
mouth to the stomach) becomes injured from the stomach acid that comes
up with the vomit.
- Hematemesis. The esophagus becomes irritated and bleeds, so
blood mixes with the vomit.
- Mallory-Weiss tear. The lower end of the esophagus may tear
open or the stomach may bruise from vomiting or retching.
- Tooth decay. The acid in the vomit can hurt the teeth by
corroding the tooth enamel.
- People with CVS have severe nausea and vomiting that come in
- CVS occurs mostly in children, but adults can have it, too.
- CVS has four phases: prodrome, episode, recovery, and symptom-free
- Most people can identify a condition or event that triggers an
episode of nausea and vomiting. Infections and emotional stress are two
- The main symptoms of CVS are severe vomiting, nausea, and retching.
Other symptoms include pallor and exhaustion.
- The only way a doctor can diagnose CVS is by looking at symptoms and
medical history to rule out any other possible causes for the nausea and
vomiting. Then the doctor must identify a pattern or cycle to the
- CVS has no cure. Treatment varies by person, but people with CVS
generally need to get plenty of rest and sleep. They may also be given
drugs that may prevent an episode, stop one in progress, speed up
recovery, or relieve symptoms.
- Complications include dehydration, loss of electrolytes, peptic
esophagitis, hematemesis, Mallory-Weiss tear, and tooth
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