Cyclic vomiting syndrome, or CVS, is a functional gastrointestinal (GI) disorder that causes sudden, repeated attacks—called episodes—of severe nausea and vomiting. Episodes can last from a few hours to several days. The episodes are separated by periods without nausea or vomiting. The time between episodes can be a few weeks to several months. Episodes can happen regularly or at random. Episodes can be so severe that you may have to stay in bed for days, unable to go to school or work. You may need treatment at an emergency room or a hospital during episodes. Cyclic vomiting syndrome can affect you for years or decades.
CVS is not chronic vomiting that lasts weeks without stopping. CVS is not a condition that has a definite cause, such as chemotherapy.
How common is cyclic vomiting syndrome?
Experts don’t know how common cyclic vomiting syndrome is in adults. However, experts believe that cyclic vomiting syndrome may be just as common in adults as in children. Doctors diagnose about 3 out of 100,000 children with cyclic vomiting syndrome every year.1
Who is more likely to get cyclic vomiting syndrome?
You may be more likely to get cyclic vomiting syndrome if you have
What are the main symptoms of cyclic vomiting syndrome?
The main symptoms of cyclic vomiting syndrome are sudden, repeated attacks—called episodes—of severe nausea and vomiting. You may vomit several times an hour. Episodes can last from a few hours to several days. Episodes may make you feel very tired and drowsy.
Each episode of cyclic vomiting syndrome tends to start at the same time of day, last the same length of time, and happen with the same symptoms and intensity as previous episodes. Episodes may begin at any time but often start during the early morning hours.
What are some other symptoms of cyclic vomiting syndrome?
Other symptoms of cyclic vomiting syndrome may include one or more of the following:
retching—trying to vomit but having nothing come out of your mouth, also called dry vomiting
How do the symptoms vary in the phases of cyclic vomiting syndrome?
The symptoms will vary as you go through the four phases of cyclic vomiting syndrome:
Prodrome phase. During the prodrome phase, you feel an episode coming on. Often marked by intense sweating and nausea—with or without pain in your abdomen—this phase can last from a few minutes to several hours. Your skin may look unusually pale.
Vomiting phase. The main symptoms of this phase are severe nausea, vomiting, and retching. At the peak of this phase, you may vomit several times an hour. You may be
quiet and able to respond to people around you
unable to move and unable to respond to people around you
twisting and moaning with intense pain in your abdomen
Nausea and vomiting can last from a few hours to several days.
Recovery phase. Recovery begins when you stop vomiting and retching and you feel less nauseated. You may feel better gradually or quickly. The recovery phase ends when your nausea stops and your healthy skin color, appetite, and energy return.
Well phase. The well phase happens between episodes. You have no symptoms during this phase.
your episode is severe and lasts more than several hours
you are not able to take in foods or liquids for several hours
You should seek medical help right away if you have any signs or symptoms of dehydration during the vomiting phase. These signs and symptoms may include
decreased skin turgor, meaning that when your skin is pinched and released, the skin does not flatten back to normal right away
sunken eyes or cheeks
light-headedness or fainting
If you are a parent or caregiver of an infant or child, you should seek medical care for them right away if they have any signs and symptoms of dehydration during the vomiting phase. These signs and symptoms may include
thirst
urinating less than usual, or no wet diapers for 3 hours or more
lack of energy
dry mouth
no tears when crying
decreased skin turgor
sunken eyes or cheeks
unusually cranky or drowsy behavior
What causes cyclic vomiting syndrome?
Experts aren’t sure what causes cyclic vomiting syndrome. However, some experts believe the following conditions may play a role:
problems with nerve signals between the brain and digestive tract
intense excitement before events such as birthdays, holidays, vacations, and school outings, especially in children
lack of sleep
physical exhaustion
allergies
temperature extremes of hot or cold
drinking alcohol
menstrual periods
motion sickness
periods without eating (fasting)
Eating certain foods, such as chocolate, cheese, and foods with monosodium glutamate (MSG) may play a role in triggering episodes.
Diagnosis
How do doctors diagnose cyclic vomiting syndrome?
Doctors diagnose cyclic vomiting syndrome based on family and medical history, a physical exam, pattern of symptoms, and medical tests. Your doctor may perform medical tests to rule out other diseases and conditions that may cause nausea and vomiting.
Family and medical history
Your doctor will ask about your family and medical history. He or she may ask for details about your history of health problems such as migraines, irritable bowel syndrome, and gastroparesis. Your doctor may also ask about your history of mental health problems, use of substances such as marijuana, and cigarette smoking.
Physical exam
During a physical exam, your doctor will
examine your body
check your abdomen for unusual sounds, tenderness, or pain
check your nerves, muscle strength, reflexes, and balance
Pattern or cycle of symptoms in children
A doctor will often suspect cyclic vomiting syndrome in a child when all of the following are present3:
at least five episodes over any time period, or a minimum of three episodes over a 6-month period
episodes lasting 1 hour to 10 days and happening at least 1 week apart
episodes similar to previous ones, tending to start at the same time of day, lasting the same length of time, and happening with the same symptoms and intensity
vomiting during episodes happening at least four times an hour for at least 1 hour
episodes are separated by weeks to months, usually with no symptoms between episodes
after appropriate medical evaluation, symptoms cannot be attributed to another medical condition
Pattern or cycle of symptoms in adults
A doctor will often suspect cyclic vomiting syndrome in adults when all of the following are present4:
three or more separate episodes in the past year and two episodes in the past 6 months, happening at least 1 week apart
episodes that are usually similar to previous ones, meaning that episodes tend to start at the same time of day and last the same length of time—less than 1 week
no nausea or vomiting between episodes, but other, milder symptoms can be present between episodes
A personal or family history of migraines supports the doctor’s diagnosis of cyclic vomiting syndrome.
Your doctor may diagnose cyclic vomiting syndrome even if your pattern of symptoms or your child’s pattern of symptoms do not fit the patterns described here. Talk to your doctor if your symptoms or your child’s symptoms are like the symptoms of cyclic vomiting syndrome.
What medical tests do doctors use to diagnose cyclic vomiting syndrome?
Doctors use lab tests, upper GI endoscopy, and imaging tests to rule out other diseases and conditions that cause nausea and vomiting. Once other diseases and conditions have been ruled out, a doctor will diagnose cyclic vomiting syndrome based on the pattern or cycle of symptoms.
Gastric emptying test, also called gastric emptying scintigraphy. This test involves eating a bland meal, such as eggs or an egg substitute, that contains a small amount of radioactive material. An external camera scans the abdomen to show where the radioactive material is located. A radiologist can then measure how quickly the stomach empties after the meal. Health care professionals perform gastric emptying tests only between episodes.
Taking medicines early in this phase can sometimes help stop an episode from happening. Your doctor may recommend over-the-counter medicines or prescribe medicines such as
During this phase, you should stay in bed and sleep in a dark, quiet room. You may have to go to a hospital if your nausea and vomiting are severe or if you become severely dehydrated. Your doctor may recommend or prescribe the following for children and adults:
medicines for
nausea
migraines
anxiety
pain
medicines that reduce the amount of acid your stomach makes
If you go to a hospital, your doctor may treat you with
IV nutrition if an episode continues for several days
Recovery phase
During the recovery phase, you may need IV fluids for a while. Your doctor may recommend that you drink plenty of water and liquids that contain glucose and electrolytes, such as
broths
caffeine-free soft drinks
fruit juices
sports drinks
oral rehydration solutions, such as Pedialyte
If you’ve lost your appetite, start drinking clear liquids and then move slowly to other liquids and solid foods. Your doctor may prescribe medicines to help prevent future episodes.
Well phase
During the well phase, your doctor may prescribe medicines to help prevent episodes and how often and how severe they are, such as
What should I eat and drink if I have cyclic vomiting syndrome?
When your nausea and vomiting stop, you can generally go back to your regular diet right away. In some cases, you may want to start with clear liquids and go slowly back to your regular diet. You should eat well-balanced and nutritious meals between your episodes. Your doctors will recommend that you not skip meals in between episodes. If you are dehydrated, drink plenty of liquids that contain glucose and electrolytes, such as
broths
caffeine-free soft drinks
fruit juices
sports drinks
oral rehydration solutions, such as Pedialyte
What should I avoid eating if I have cyclic vomiting syndrome?
In between episodes, you should avoid eating foods that may have triggered past episodes. Eating certain foods such as chocolate, cheese, and foods with monosodium glutamate (MSG), may trigger an episode in some people. Adults should avoid drinking alcohol.
Clinical Trials
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.
What are clinical trials and are they right for you?
Clinical trials are part of clinical research and at the heart of all medical advances. Clinical trials look at new ways to prevent, detect, or treat disease. Researchers also use clinical trials to look at other aspects of care, such as improving the quality of life for people with chronic illnesses. Find out if clinical trials are right for you.
Watch a video of NIDDK Director Dr. Griffin P. Rodgers explaining the importance of participating in clinical trials.
What clinical trials are open?
Clinical trials that are currently open and are recruiting can be viewed at www.ClinicalTrials.gov.
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases
(NIDDK), part of the National Institutes of Health. NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts.
The NIDDK would like to thank: Thangam Venkatesan, M.D., Medical College of Wisconsin