What are the causes of nausea?

From the Guidelines

Nausea is primarily caused by gastrointestinal issues, medications, and systemic illnesses, with approximately 70% to 80% of cancer patients on chemotherapy experiencing nausea and/or vomiting, as reported by 1. The causes of nausea can be diverse and multifaceted, including:

• Gastrointestinal issues such as food poisoning, gastroenteritis, GERD, peptic ulcers, and gastroparesis
• Medications like chemotherapy drugs, antibiotics, pain relievers, and anesthetics, which can trigger nausea as a side effect, as noted in 1 and 1
• Systemic illnesses, including infections, gallbladder disease, pancreatitis, appendicitis, and kidney disorders, which frequently present with nausea
• Hormonal changes during pregnancy, often leading to morning sickness, particularly in the first trimester
• Inner ear disturbances causing motion sickness, migraine headaches, and emotional stress, which can all provoke nausea
• Neurological issues like increased intracranial pressure, concussions, or vestibular disorders, which may also cause nausea Treatment of nausea depends on identifying the underlying cause, but may include antiemetic medications like metoclopramide, which has the strongest evidence supporting its use, as stated in 1. Additionally, staying hydrated, eating small bland meals, and avoiding triggering foods or activities can help manage nausea. It is essential to note that nausea serves as a protective mechanism, warning the body of potential toxins or problems, which explains why so many different conditions can trigger this common symptom.

From the FDA Drug Label

Dopamine produces nausea and vomiting by stimulation of the medullary chemoreceptor trigger zone (CTZ) The cause of nausea is dopamine stimulation of the medullary chemoreceptor trigger zone (CTZ) 2.

From the Research

Causes of Nausea

• Typical causes of acute nausea and vomiting include:
  • Gastroenteritis or other viral syndromes 3
  • Foodborne illness 3
  • Acute migraine headaches 3
  • Vestibular disturbances 3
  • Early pregnancy 3
  • Adverse effects of medication 3
• Chronic nausea and vomiting have a broad differential diagnosis, with causes that can be:
  • Gastrointestinal 3, 4
  • Infectious 3
  • Metabolic 3
  • Neurologic 3, 5
  • Psychiatric 3
  • Related to medications and toxins 3
• Other specific causes of nausea include:
  • Post-operative nausea 6
  • Chemotherapy-induced nausea 6
  • Motion sickness 6
  • Gastroparesis 4, 7
  • Cyclic vomiting syndrome 4
  • Dysmotility symptoms, such as epigastric discomfort or fullness, and early satiety, associated with gastroesophageal reflux disease (GERD) 7

Pathophysiology of Nausea

• Nausea is considered to function as a protective mechanism, warning the organism to avoid potential toxic ingestion 6
• The sensation of nausea results from continuous interactions among gastrointestinal, central nervous system, and autonomic nervous system 5
• Central pathways of nausea and vomiting appear to be at least partly different, and nausea is no longer considered only a penultimate step of vomiting 5