Cyclic Vomiting Syndrome (CVS): Symptoms, Causes & UK Management

Cyclic Vomiting Syndrome (CVS) is a relatively rare but debilitating condition characterised by sudden, intense bouts of vomiting and nausea. Unlike common gastroenteritis or food poisoning, these episodes are recurrent and can occur at regular intervals. Between these episodes, patients typically feel completely healthy.

In the UK, CVS is often underdiagnosed in adults because the symptoms can mimic other digestive disorders such as GORD, gastroparesis, or even severe food intolerances. However, the pattern of 'on-off' symptoms is the hallmark of the condition. While it was once thought to be a paediatric condition, it is now widely recognised by the NHS and specialists as a condition that affects adults, sometimes persisting for decades if not managed correctly.

CVS typically progresses through four distinct stages. Understanding these phases can help you and your healthcare provider manage the condition more effectively:

• The Prodrome Phase: This is the 'warning' period where you may feel intense nausea, sweating, or abdominal pain. It can last from a few minutes to several hours.
• The Vomiting Phase: This is the peak of the episode. It involves frequent vomiting (sometimes several times an hour), intense nausea, and often a sensitivity to light and sound. Some patients may also experience abdominal pain or diarrhoea.
• The Recovery Phase: This begins when the vomiting stops. Nausea gradually fades, and appetite begins to return.
• The Well Phase: This is the period between episodes where no symptoms are present. This period can last for weeks, months, or even years.

While the exact cause of Cyclic Vomiting Syndrome remains unknown, research suggests a strong link to migraine headaches. Many adults with CVS find that their vomiting episodes are triggered by the same factors that cause migraines. According to NICE clinical summaries, common triggers include:

• Emotional stress: Both positive excitement and negative stress or anxiety.
• Infections: Recurrent colds, flu, or sinus infections.
• Dietary factors: Certain foods like chocolate or cheese, or skipping meals.
• Physical exhaustion: Lack of sleep or overexertion during exercise.
• Hormonal changes: Many women find episodes correspond with their menstrual cycle.

Identifying your personal triggers is a crucial part of long-term management and can significantly reduce the frequency of attacks.

There is currently no single cure for CVS, but treatment is highly effective at reducing the impact on your life. Management is usually divided into two categories:

Abortive Treatment

This is used at the very start of the prodrome phase to try and stop the episode from progressing. Doctors may prescribe anti-sickness (anti-emetic) medications or triptans (medications usually used for migraines) to halt the cycle.

Preventative Treatment

If episodes are frequent or severe, a GP may suggest daily medication to prevent them from occurring. This often includes low-dose antidepressants (such as amitriptyline) or certain blood pressure medications, which have been shown to stabilise the nerve signals that cause vomiting.

During an active vomiting phase, the primary risk is dehydration. Sipping small amounts of water or using oral rehydration salts is essential. If you cannot keep any fluids down, hospital intervention for IV fluids may be required.

Managing recurrent vomiting can be exhausting and isolating. Speaking to an online doctor in the UK is an excellent first step if you are experiencing a pattern of illness that you cannot explain. An online consultation allows you to discuss your history in detail without the stress of travelling while feeling unwell.

A GP can help by:

• Reviewing your symptom diary to identify a 'cyclic' pattern.
• Providing prescriptions for anti-sickness medications to keep at home for future episodes.
• Discussing the need for further tests, such as blood tests or a referral to a gastroenterologist, to rule out other conditions like gallstones or stomach ulcers.
• Issuing a sick note if your episodes are frequent enough to affect your ability to work.

Alongside medical treatment, lifestyle adjustments can help you regain control. We recommend keeping a 'symptom diary' to track food, sleep, and stress levels before an episode. Ensuring you have a 'rescue kit' at home—consisting of prescribed medications, rehydration sachets, and a quiet, dark room—can make the vomiting phase more manageable. Following the 'migraine diet' (avoiding triggers like caffeine and MSG) may also provide relief for some individuals.