Nausea is an unpleasant feeling of discomfort or unease in the stomach. It often happens before vomiting.
Nausea and vomiting do not constitute a standalone condition. However, there are many possible causes of these symptoms, including motion sickness, infections, migraine, food poisoning, gallbladder disease, intense pain, surgery, pregnancy, indigestion, and emotional stress.
In this article, learn more about the causes of nausea and vomiting and what to do if they happen.
There are many possible causes of nausea and vomiting, including those below:
The symptoms usually start within the first 9 weeks of pregnancy and often disappear by week 14. However, they can sometimes persist throughout the pregnancy.
Severe nausea and vomiting, called hyperemesis gravidarum, affects about 3% of pregnancies. If there is a risk of dehydration, it may be necessary to seek medical treatment and spend time in the hospital.
Central nervous system
Many diseases and conditions that affect the central nervous system (CNS) have nausea as a symptom.
Experts do not know why many CNS problems cause nausea and vomiting.
Related to CNS disorders are inner ear (vestibular) problems, which can affect a person’s sense of balance. This effect can lead to vertigo, nausea, and vomiting.
Conditions that affect the inner ear include:
- Motion sickness: Some modes of transport and fairground rides can trigger this.
- Labyrinthitis: This inner ear infection usually occurs due to a virus.
- Benign positional vertigo: A small movement, such as moving the head, can trigger a spinning sensation.
- Ménière’s disease: This long-term ear condition can affect a person’s balance and cause dizziness, vertigo, tinnitus, and hearing loss.
Pelvic and abdominal conditions
Many pelvic and abdominal conditions have nausea as a symptom. These conditions can affect the gastrointestinal tract, the reproductive system, the liver, and other parts of the body, depending on the cause.
The following are just a few examples:
- obstruction or irritation in the digestive system
- gastroesophageal reflux disease (GERD)
- kidney disease
- gallbladder disease
- infections, such as gastroenteritis
Anxiety, depression, and stress
Psychological conditions that can induce nausea include:
Some types of cancer can cause nausea and vomiting. These include:
- a brain tumor
- cancer that causes a blockage to the bowel
- cancer anywhere in the gastrointestinal system
- a tumor in the appendix or pancreas
- lung cancer
- ovarian cancer
Nausea and vomiting are also common side effects of cancer therapy.
Medication can help manage symptoms and prevent complications. Possible complications include a loss of appetite, damage to the esophagus, dehydration, malnutrition, and a reopening of surgical incisions.
The cancer treatments that most commonly cause nausea are:
The severity of symptoms will depend on various factors, including the type and dosage of treatment and how the person’s body responds to it.
The risk is higher when treatment involves the brain, liver, or gastrointestinal tract. It also increases with higher doses.
People may have an increased risk of severe symptoms from chemotherapy or radiation therapy if they:
- experienced severe and frequent nausea and vomiting during previous treatment
- are female
- are under 50 years of age
- have constipation
- are taking certain medications, such as opioids
- have anxiety
- have an infection
- have kidney disease
- have an electrolyte or fluid imbalance in their body
Cyclical vomiting syndrome
This rare condition usually occurs in children. The individual will have episodes of nausea and vomiting for no clear reason. They will then feel well but may have another episode, perhaps a month later.
The cause is unclear, but there may be a link with migraine.
Other possible causes include:
- stress or anxiety
- dietary factors
- recurrent infections
- excessive physical exercise
- a lack of sleep
Common causes of vomiting in young children include:
- minor intestinal infections
- chest, urine, or other infections
- a food allergy or intolerance
- food poisoning
- some serious conditions, such as meningitis and appendicitis
People often link teething with vomiting, but experts do not consider there to be a link.
Nausea and vomiting are usually temporary symptoms that go away on their own, but they can sometimes indicate a more serious condition.
It is important to seek medical advice if the following symptoms also occur:
- severe stomach pain
- blood in the vomit
- vomiting that lasts longer than 24 hours
- a severe headache
- a stiff neck
Treating the underlying cause may also relieve nausea and vomiting.
Vomiting is common in infants and young children, and it is often not a cause for concern.
However, parents or caregivers should seek medical attention if vomiting continues for more than a day or two, or the following symptoms are present:
- signs of dehydration, such as dry lips, sunken eyes, and infrequent urination
- frequent and forceful vomiting
- green or greenish-yellow vomit
- blood in vomit or stools
- refusing to feed
- any other concerning symptoms
The treatment for nausea and vomiting will depend on the cause, but some medications — known as antiemetics — can help manage the symptoms.
There are several over-the-counter options. If these are not effective, a doctor may prescribe a stronger drug.
People should take care when using any medications and always:
- read the directions on the package
- follow the instructions regarding how much to take and when
- check with a doctor before using any new medication
- seek medical advice if they cannot keep the medication down
Examples include dimenhydrinate (Dramamine) and meclizine hydrochloride (Dramamine Less Drowsy).
To avoid motion sickness when traveling, it is best to take these drugs just before the trip.
Side effects may include:
- dry eyes
- dry mouth
People who take sedatives, muscle relaxants, or sleeping pills should check with their doctor before using antihistamines.
There are also treatments specific to:
- morning sickness
- sickness due to cancer treatment
- gastrointestinal problems due to diabetes and other conditions
- cyclical vomiting syndrome
A doctor can advise on suitable options.
Herbal and alternative remedies
Some people use alternative remedies, such as:
It is not always possible to avoid nausea and vomiting, but people may be able to prevent or manage symptoms by:
- drinking plenty of water, taking sips, if necessary, to prevent vomiting
- drinking ginger or peppermint tea
- eating regular meals and avoiding heavy, greasy food
- letting in some fresh, cool air
- sitting upright after eating to avoid reflux
- avoiding tight clothing
- washing the hands frequently to reduce the risk of infections
- seeing a doctor if nausea and vomiting are frequent and unexplained
Nausea and vomiting are common symptoms of many diseases and conditions. These symptoms often go away without treatment, but various options can help prevent or manage them.
Anyone with nausea and vomiting that are severe, persistent, cause dehydration, or occur alongside additional symptoms should see a doctor.