Understanding Nausea and Vomiting: Causes and Mechanisms

Nausea is a distinct feeling of discomfort and urgency in the upper abdomen, often serving as a precursor to vomiting but can also occur independently. Vomiting, on the other hand, is a complex reflex action that forcefully expels gastric or small intestinal contents through the esophagus and mouth.

Causes of Nausea and Vomiting

The causes of nausea and vomiting are diverse and can be categorized based on their underlying mechanisms:

1. Reflex Vomiting

Reflex vomiting is triggered by irritation or diseases affecting various organs:

• Pharyngeal Irritation:
• Exposure to irritating gases (e.g., ammonia).
• Severe coughing or inflammation of the posterior nasal passages.
• Chronic pharyngitis or passive smoking.
• Gastrointestinal Diseases:
• Inflammations or ulcers of the stomach and duodenum.
• Pyloric obstruction or gastric dilatation due to overeating.
• Duodenal congestion or diverticulitis.
• Liver, Gallbladder, Pancreas, and Peritoneal Diseases:
• Acute hepatitis (e.g., type A, type E, drug-induced).
• Advanced liver cirrhosis, liver abscess, or acute and chronic cholecystitis.
• Gallstones, acute pancreatitis, or acute peritonitis.
• Cardiovascular Diseases:
• Acute myocardial infarction, shock, or heart failure.
• Other Causes:
• Glaucoma, refractive errors, acute pyelonephritis, renal colic, pelvic inflammatory disease, infectious diseases, early pregnancy, or ectopic pregnancy.

2. Central Vomiting

Central vomiting originates from the central nervous system and includes:

• Central Nervous System Diseases:
• Infections, cerebrovascular diseases (e.g., cerebral hemorrhage, embolism, thrombosis).
• Intracranial hypertension, migraines, or craniocerebral trauma.
• Drug or Toxin Effects:
• Antibiotics, chemotherapy drugs, digitalis, morphine, or chemical toxins.
• Epilepsy:
• Particularly during status epilepticus.
• Other Causes:
• Metabolic disorders (e.g., hyponatremia, ketoacidosis, uremia).
• Pregnancy-induced hypertension, thyroid crisis, Addison’s disease crisis, or hypoglycemia.

3. Vestibular Vomiting

Vestibular vomiting is associated with inner ear disorders:

• Inner ear labyrinthine lesions.
• Labyrinthitis or Meniere’s disease.
• Motion sickness.

4. Neurotic Vomiting

Neurotic vomiting is linked to psychological or neurological conditions:

• Gastric neurosis.
• Anorexia nervosa.
• Miasma or other psychological factors.

Conclusion

Understanding the diverse causes of nausea and vomiting is essential for accurate diagnosis and effective management. These symptoms can arise from a wide range of conditions, including gastrointestinal, neurological, cardiovascular, and psychological disorders. Consulting a healthcare provider is crucial for identifying the underlying cause and determining the appropriate treatment.