Nausea And Vomiting Causes

What Is Nausea And Vomiting

Nausea is the feeling of a need to vomit. Before vomiting nausea occurs, but nausea is not always results vomiting. So nausea and vomiting are related. It is a subjective feeling. It means nausea is the feeling that differs from person to person. It is an uncomfortable feeling, but the level of discomfort varies from person to person.

Vomiting (also known as emesis) is the oral expulsion of gastrointestinal contents due to gut and thoracoabdominal wall contractions. Simply means, vomiting is the expulsion of food or other stomach contents from stomach to outside of the mouth. Before vomiting, there is always a urge to vomit. This is the worst feeling that no one wants to experience.

Nausea and vomiting are not uncommon. In fact, in many medical conditions, nausea and vomiting are usual symptoms. People all over the world at some point of time experience nausea and vomiting. In this article we are going to discuss in detail about nausea and vomiting. Lets check.

Normally food that enters the stomach from the food pipe (esophagus), should not go back to the food pipe (esophagus). But during vomiting the food and other contents from the stomach goes back to the food pipe (esophagus) and comes out from the mouth. This is known as the vomiting.

Nausea And Vomiting Triggering Factors

Nausea and vomiting stimuli or triggering factors are present at different sites in our body. The triggering factors are the following

  1. Unpleasant thought
  2. Unpleasant smell
  3. Unpleasant sight
  4. Motion sickness
  5. Gag reflex activation
  6. Inner ear disorders
  7. Gastric irritants
  8. Circulating toxins
  9. Hypoxia
  10. Uremia
  11. Ketoacidosis

Nausea And Vomiting Causes

There are wide range of reasons that can cause nausea and vomiting. Nausea and vomiting can be caused by conditions within and outside the gut, by drugs, and by circulating toxins. Rarely, in 2% to 3% of the cases there is unexplained cause of chronic nausea and vomiting. So the causes of nausea and vomiting are the following

Intraperitoneal Cause (Within the peritoneum causes)

Obstructing Disorders

  • Pyloric obstruction (can be due to ulcer or malignancy)
  • Small-bowel obstruction
  • Colonic obstruction
  • Superior mesenteric artery syndrome – This syndrome occur after weight loss or prolonged bed rest. It results when the duodenum is compressed by the overlying superior mesenteric artery.

Small-bowel obstruction and colon blockage or obstruction occur due to adhesions, benign or malignant tumors, volvulus, intussusception, or inflammatory diseases like Crohn’s disease.

  • Obstruction or inflammation in any organ can cause vomiting.

Enteric Infections

  • Bacterial infection (Staphylococcus aureus and Bacillus cereus cause vomiting, especially in children)
  • In persons with weak immunity (immunocompromised), opportunistic infections such as cytomegalovirus or herpes simplex virus can cause vomiting.

Inflammatory Diseases

  1. Cholecystitis
  2. Pancreatitis
  3. Appendicitis
  4. Hepatitis

It is important to mention that in the above mentioned conditions (pancreatitis, cholecystitis, and appendicitis), vomiting occurs due to organ (visceral) irritation.

Altered Sensorimotor Function

  • Gastroparesis- Gastroparesis has symptoms of gastric retention with delayed gastric emptying. It usually occurs after vagotomy or with pancreatic carcinoma, mesenteric vascular insufficiency, or diseases like diabetes, scleroderma, and amyloidosis. Idiopathic gastroparesis can also occur.

In idiopathic gastroparesis, no cause behind the gastroparesis is found. Idiopathic gastropareis occurs in the absence of systemic illness and follows a viral illness in approximately 15–20% of cases, suggesting an infectious trigger.

  • Intestinal pseudoobstruction – Intestinal pseudoobstruction has disrupted intestinal and colonic motor activity with retention of food residue and secretions; bacterial overgrowth; nutrient malabsorption; and symptoms of nausea, vomiting, bloating, pain, and altered defecation or stool habits.
  • Gastroesophageal reflux- In this condition nausea and vomiting can occur.
  • Chronic nausea vomiting syndrome – This is a syndrome when there is nausea at least one day and/or one or more vomiting episodes weekly in the absence of an eating disorder or psychiatric disease.
  • Cyclic vomiting syndrome- This syndrome causes 3–14% of cases of unexplained nausea and vomiting. This condition is associated with periodic discrete episodes of relentless vomiting in children and adults. It also shows migraine headaches.
  • Cannabinoid hyperemesis syndrome- This condition shows cyclical vomiting with intervening well periods in persons (mostly men) who use large quantities of cannabis over many years and the vomiting resolves with the discontinuation of cannabis.
  • Rumination syndrome- In this condition there is repetitive regurgitation of recently ingested food. It is often misdiagnosed as refractory vomiting. So, proper evaluation is needed to confirm this condition.

Biliary Colic

Biliary colic causes nausea by acting on local nerves (afferent nerves).

Abdominal Irradiation

Abdominal irradiation impairs intestinal motor function and induces strictures. This can cause nausea and vomiting.

Extraperitoneal Cause

Cardiopulmonary (Heart and Lung) Disease

  • Cardiomyopathy
  • Myocardial infarction

Labyrinthine Disease

  • Motion sickness
  • Labyrinthitis
  • Malignancy

Intracerebral Disorders

  • Malignancy
  • Hemorrhage
  • Abscess
  • Hydrocephalus

In the above mentioned conditions there are increased intracranial pressure that induce vomiting.

Psychiatric Illness

In the psychiatric illness, delayed gastric emptying may be the possible reason that induce vomiting.

Postoperative Vomiting

Postoperative vomiting means vomiting that occur after surgery. Postoperative vomiting occur after 25% of surgeries. In the majority of cases, after abdominal surgery or orthopedic surgery postoperative vomiting is seen.

Medications/Metabolic Disorders


  • Cancer chemotherapy
  • Antibiotics
  • Cardiac antiarrhythmics
  • Digoxin
  • Oral hypoglycemics
  • Oral contraceptives
  • Antidepressants (selective serotonin and serotonin norepinephrine reuptake inhibitors)
  • Restless legs/Parkinson’s therapies
  • Smoking cessation agents (varenicline, nicotine)

Hormonal (endocrine) and Metabolic Disease

  • Pregnancy (In the first trimester, 70% of women experience nausea)
  • Uremia
  • Ketoacidosis
  • Thyroid and parathyroid disease
  • Adrenal insufficiency


  • Liver failure
  • Ethanol

Toxins can be generated by liver failure. Toxins can also be produced due to enteric bacterial infections. All these circulatory toxins cause vomiting.

Ethanol intoxication can also result in nausea and vomiting.


Nausea and vomiting are unwanted feeling. There are wide range of reasons, as mentioned above, that can cause nausea and vomiting. The triggering factors for nausea and vomiting must be avoided to get relief from nausea and vomiting.

Treatment is based upon the cause. So prompt diagnosis of the cause or triggering factor that is causing vomiting or nausea is vital. You should not ignore if there is vomiting or nausea. Follow the doctor’s instructions. Stay healthy and happy.


  1. Psychiatry, 2 Volume Set Book By Wiley
  2. Year Book of Psychiatry and Applied Mental Health 2012
  3. Textbook of Psychiatry E-Book, Elsevier

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