Understanding Vomiting: Causes, Reflex, and When to Seek Help

Vomiting is a protective reflex expelling harmful substances from the stomach/intestines. Illness produces toxins/bacteria that irritate the GI lining, triggering the reflex—stomach muscles contract, expelling contents.

Common Causes

• GI infections: Food poisoning, norovirus, rotavirus → inflammation, irritation.
• Stomach flu (viral gastroenteritis): Inflammation → vomiting, diarrhea, abdominal pain.
• Food allergies: Immune response → inflammation, vomiting.
• Motion sickness: Conflicting sensory signals → nausea, vomiting.
• Pregnancy: Hormonal changes cause nausea/vomiting.

Usually resolves in days. See a doctor for severe or persistent vomiting to rule out underlying conditions.