Differential Diagnosis for Nausea

• Single most likely diagnosis:
  • Gastroenteritis: This is often the most common cause of nausea, typically resulting from a viral or bacterial infection that leads to inflammation of the stomach and intestines. The justification for this being the single most likely diagnosis is its high prevalence and the broad range of potential exposures to pathogens that can cause it.
• Other Likely diagnoses:
  • Food poisoning: Similar to gastroenteritis, food poisoning is a common cause of nausea, usually occurring after consuming contaminated or spoiled food.
  • Viral gastroenteritis (e.g., norovirus): Highly contagious and common, especially in closed environments like cruise ships, schools, and hospitals.
  • Motion sickness: A frequent cause of nausea in individuals traveling by car, boat, plane, or other vehicles, particularly if they are prone to motion sickness.
  • Pregnancy: Morning sickness is a well-known symptom of early pregnancy, affecting a significant number of pregnant women.
  • Medication side effects: Many medications can cause nausea as a side effect, including antibiotics, pain relievers, and chemotherapy drugs.
• Do Not Miss diagnoses:
  • Appendicitis: Although less common, appendicitis can present with nausea and vomiting, and missing this diagnosis can lead to severe consequences, including perforation and peritonitis.
  • Myocardial infarction (heart attack): In some cases, especially in women, nausea and vomiting can be symptoms of a heart attack, making it crucial not to overlook this potentially life-threatening condition.
  • Pancreatitis: Inflammation of the pancreas can cause severe nausea and vomiting, and early diagnosis is critical for effective management.
  • Intestinal obstruction: This condition, where part of the intestine is blocked, can lead to severe nausea and vomiting and requires prompt medical attention.
• Rare diagnoses:
  • Migraines: Some individuals experience nausea and vomiting as part of their migraine symptoms.
  • Inner ear disorders (e.g., labyrinthitis, vestibular neuritis): These can cause vertigo, nausea, and vomiting due to the inner ear's role in balance.
  • Brain tumors or cysts: In rare cases, increased intracranial pressure from a brain tumor or cyst can cause nausea and vomiting.
  • Porphyrias: A group of rare genetic disorders that can cause a variety of symptoms, including nausea and vomiting, often in response to certain medications or hormonal changes.