Vomiting alone (unrelated to food and without abdominal pain or headaches)

Some differential diagnoses and typical outline evidence

Gastroenteritis	Suggested by: diarrhoea, decreased bowel sounds.
	Confirmed by: stools for WBC and culture.
	Management: OHCM p556.
Sliding hiatus hernia	Suggested by: occasional chest pain precipitated by heavy meals, lying flat.
	Confirmed by: barium meal showing reflux.
	Management: OHCM p216.
Acute viral labyrinthitis	Suggested by: vertigo, nystagmus.
	Confirmed by: being self-limiting over days.
	Management: OHCM p346–7.
Ménière's disease	Suggested by: vertigo, tinnitus, deafness.
	Confirmed by: audiometry: sensory hearing loss.
	Management: OHCM p346, OHCS p554.
Pregnancy	Suggested by: being worse soon after waking, amenorrhoea.
	Confirmed by: pregnancy test +ve.
Anaphylaxis	Suggested by: bronchospasm, laryngeal oedema, flushing, urticaria, angioedema.
	Confirmed by: relief with antihistamines or steroids.
	Management: OHCM p780, OHCS p237.
Renal failure (CRF)	Suggested by: fatigue, pruritus, anorexia, nausea, ‘lemon-tinge’ skin.
	Confirmed by: ↑serum creatinine, ↓creatinine clearance. If chronic CRF: Hb low, and small kidneys on renal ultrasound.
	Management: OHCM pp272–4.
Addison's disease	Suggested by: lethargy, weakness, dizziness, pigmentation (buccal, scar), hypotension.
	Confirmed by: 9 a.m. plasma cortisol low ↓ and impaired response to short ACTH stimulation test (short Synacthen test).
	Management: OHCM p312.
Drugs e.g. antibiotics, cytotoxics, any overdose, excessive alcohol ingestion etc.	Suggested by: history of drug ingestion.
	Confirmed by: response of symptoms to avoidance of drug.
Functional	Suggested by: vomiting during or soon after a meal ± other psychological disturbance and no symptoms and physical signs of organic disease.
	Confirmed by: response to psychotherapy.