Vomiting (or emesis), which is the forceful ejection of contents of the upper gut through the mouth.

Terms often confused with vomiting

- Retching involves coordinated, voluntary muscle activity of the abdomen and thorax--in effect, a forced respiratory inspiration against a closed mouth and glottis without discharge of gastric contents from the mouth.

- Regurgitation is the effortless return of gastric or esophageal contents into the mouth without nausea, and it occurs without spasmodic, abdominal, thoracic, or gastrointestinal muscular contractions (i.e. Retching).

Although it is doubtful if breaking separating the causes of nausea from those of vomiting is clinically useful, it does help to put the differential diagnosis into perspective.

1. Vomiting associated with nausea

This is most frequently due to a cause affecting the chemoreceptor trigger zone (medulla oblongata).

1. Neurological

Accompanying neurological manifestations

  • Migraine
    Clinical suspicion: nausea & headache
  • Labyrinthine disorders:
    Clinical suspicion: nausea & vertigo
  • Cerebral lesion (increase intracranial lesion)
    Clinical suspicion: blurring of vision, headache, projectile vomiting, focal neurological manifestations.

2. Metabolic

Toxic, maybe delirious,
Labs, pH, electrolytes

  • DKA
  • Metabolic acidosis
  • Electrolyte abnormalities

  • Renal failure
  • Hepatic failure

  • Hypothyroidism
  • Adrenal insufficiency

  • Drugs & toxins

  • Pregnancy (Morning sickness, hyperemesis gravidarum)
  • Food allergy

3. GIT Causes

  • Over-eating or drinking too much alcohol
  • Many patients experience nausea after eating spoiled food
  • Gallstones, gastroenteritis and stomach ulcer may cause nausea and vomiting

4. Other Causes

  • Motion sickness can be induced by traveling in a vehicle, plane, or on a boat.

3. Psychogenic


By exclusion

Persistent, unexplained, or recurring nausea and vomiting can be symptoms of a variety of serious illnesses. You should seek medical assessment if:

  • After eating rich or spoiled food or taking a new medication
  • Repeatedly or for 48 hours or longer
  • Following intense dizziness.

It is important to see a doctor if nausea and vomiting are accompanied by:

  • Jaundice
  • Pain in the chest or lower abdomen
  • Trouble with swallowing or urination
  • Dehydration or extreme thirst
  • Drowsiness or confusion
  • Constant, severe abdominal pain
  • A fruity breath odor

2. Vomiting without nausea

 i.e. chemoreceptor trigger zone (CTZ) in the brain is not affected. Usually a local gastro-intestinal cause.

1. Pain induced

Vomiting & pain

Visceral pain which is usually of GIT origin but maybe related to other organs e.g. myocardial infarction.

  • Gastro-duodenal: ulcer
  • Gastro-intestinal: inflammation
  • Hepatobiliary: inflammation
  • Pancreas: inflammation, cancer
  • Peritoneum: inflammation, cancer
  • Other: Myocardial infarction.

2. Obstructive

Vomiting, abdominal swelling, absolute constipation

  • Pyloric: copious brownish acid vomitus
  • Duodenal: bile
  • Intestinal: fecal

3. Infective

vomiting & fever, diarrhea

e.g. gastro-enteritis.

4. Other GIT causes

vomiting & other GIT manifestations

e.g. congestive heart failure leading to gut congestion.

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