Nausea and Vomiting – Diagnosis, Symptoms, and Treatment

Medically Reviewed by Dr. Po-Chang Hsu, MD, MS

Medically reviewed by Dr. Po-Chang Hsu, MD, MS

Medical Professional

Updated - January 11, 2021

Dr. Po-Chang Hsu is a medical doctor from Tufts University in Boston, Massachusetts, interested in pediatrics and neonatology.

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What is Nausea and Vomiting?

Nausea and vomiting (emesis) are common symptoms that may accompany a variety of medical disorders.  Gastrointestinal disorders that are frequently responsible include gastroenteritis, inflammatory bowel disease, or bowel obstruction.  Diseases in other organ systems may also manifest with nausea and vomiting – these typically include central nervous system disorders (e.g., migraine headache) and cardiovascular conditions (e.g., heart attack, angina).  Certain medications (e.g., antibiotics, corticosteroids) can also provoke gastrointestinal discomfort and vomiting.

Normal physiologic processes such as pregnancy can also lead to nausea and vomiting.  A severe form of vomiting called hyperemesis gravidarum is particularly problematic and associated with high morbidity.  Cancer and chemotherapy are also closely associated with vomiting.  Occasionally, nausea and vomiting are the primary symptoms, and an etiology cannot be identified (functional nausea and vomiting).

What Causes Nausea and Vomiting?

Nausea and vomiting are often a manifestation of gastrointestinal disease. However, they may also represent symptoms of another systemic disorder.  The following conditions are frequently associated with nausea and vomiting:

  •         Gastrointestinal diseases: food poisoning, viral gastroenteritis, hepatobiliary disease, gallstones, peptic ulcer disease, bowel obstruction, appendicitis, cholecystitis, diabetic gastroparesis, esophageal stricture, pyloric stenosis
  •         Cardiovascular: myocardial infarction, angina, bradycardia
  •         Cancer: any advanced-stage cancer
  •         Neurologic disorders: migraine headache, increased intracranial pressure, brain tumor, intracranial hemorrhage
  •         Vestibular disorders: motion sickness, vertigo,
  •         Metabolic disorders: diabetic ketoacidosis
  •         Urinary: pyelonephritis, kidney stones (nephrolithiasis)
  •         Substance use: alcohol intoxication or withdrawal, marijuana use
  •         Infectious diseases: HIV/AIDS
  •         Medication side effect: antibiotics, NSAIDs, corticosteroids, chemotherapy

Nausea and vomiting may also represent a physiologic response to noxious smells or emotionally disturbing sites.

How Common is Nausea and Vomiting?

Nausea and vomiting are exceedingly common symptoms that are often evaluated in the primary care clinic, emergency department, and hospitalized patients.  Severe or advanced cases often require referral to a gastroenterology specialist, especially if first-line measures are unsuccessful.

About 4% of emergency department visits are related to the chief complaint of nausea and vomiting.  An estimated 74% of pregnant women experience nausea or vomiting.  Approximately 50% of these patients only have vomiting without nausea.  Hyperemesis gravidarum is a condition characterized by severe persistent symptoms refractory to therapy and results in dehydration and other complications.  Up to 1% of pregnant women suffer from the condition.

Signs and Symptoms

Nausea and vomiting are often associated with other symptoms that may explain the underlying cause of emesis.  Individuals with chest pain, shortness of breath, and diaphoresis likely have a heart attack.  Patients with headaches, visual changes, and bradycardia likely have an intracranial bleed or mass.  Patients with fever, malaise, body aches, and abdominal discomfort may have viral gastroenteritis.  Those with weight loss, anorexia, and loss of appetite have features worrisome for underlying cancer.  Individuals with pyelonephritis often experience back pain, burning on urination, urinary frequency, and blood in the urine.


Individuals typically have routine blood tests performed to determine the etiology of symptoms and evaluate complications such as dehydration, hypokalemia, metabolic alkalosis, and acute kidney injury.  Commonly ordered blood tests include a CMP (comprehensive metabolic panel), CBC (complete blood cell count), and thyroid function (TSH, free T4).  A urinalysis and urine pregnancy test are also obtained.

If you have associated gastrointestinal symptoms such as abdominal distension or severe abdominal pain, your doctor will typically order an abdominal ultrasound or CT scan.  Your doctor may recommend an upper endoscopy if you have difficulty swallowing (dysphagia) or pain on swallowing (odynophagia).  During this procedure, a camera is advanced down the esophagus into the stomach and small intestine.

Your doctor may want to evaluate a neurologic disorder such as intracranial hemorrhage or tumor if you have associated headaches.  Depending on your clinical features, they may recommend obtaining a computed tomography (CT) scan or magnetic resonance imaging (MRI) of the head.

If you have associated chest pain, shortness of breath, or diaphoresis (profuse sweating), this could suggest a heart attack.  Your doctor will typically order an EKG (electrocardiogram) to evaluate the electrical activity of your heart.  They may also order serum cardiac enzymes to evaluate for heart muscle injury.

Nausea and Vomiting Treatment

The treatment is first aimed at reversing a known cause if possible.  Patients with significant symptoms often require the use of antiemetic medications.  The choice of antiemetic therapy is based on the suspected cause of symptoms.

Individuals with nausea and vomiting associated with migraine headaches often benefit from using dopamine receptor antagonists such as Reglan (metoclopramide) or Compazine (prochlorperazine).  Individuals with vestibular dysfunction such as motion sickness or vertigo typically improve with antihistamines such as Antivert (meclizine) or anticholinergic medications.  Pregnancy-induced vomiting is typically treated with Phenergan (promethazine) or serotonin antagonists (e.g., Zofran - ondansetron).

Gastroenteritis is usually treated with dopamine receptor antagonists or serotonin antagonists.  Postoperative nausea and vomiting often respond well to serotonin antagonists or Inapsine (droperidol).  Serotonin antagonists are one of the most widely used classes of antiemetics – these are the preferred agents for nausea and vomiting associated with chemotherapy.  They are also useful for most other causes of nausea and vomiting.  The majority of the medications above are available in oral and intravenous formulations.

Dopamine antagonists can be associated with extrapyramidal side effects such as acute dystonia and are occasionally co-administered with antihistamines such as Benadryl (diphenhydramine) to prevent such occurrences.


  1.     Hasler WL, Chey WD. Nausea and vomiting. Gastroenterology 2003; 125:1860.
  2.     American Gastroenterological Association. American Gastroenterological Association medical position statement: nausea and vomiting. Gastroenterology 2001; 120:261.

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.