Vomiting with headache alone (unrelated to food and no abdominal pain)

Some differential diagnoses and typical outline evidence

Migraine	Suggested by: throbbing headache with preceding visual auras or other transient sensory symptoms and ‘trigger’ factors e.g. pre-menstrual, stress, particular foods.
	Confirmed by: history, but if in doubt MRI scan to exclude anatomical abnormalities.
	Management: OHCM p342.
Raised intracranial pressure	Suggested by: being worse in morning, on coughing and leaning forward, papilloedema.
	Confirmed by: CT scan head showing flattening of sulci and darkening of brain tissue.
	Management: OHCM p816.
Meningitis (viral or bacterial)	Suggested by: photophobia, fever, neck stiffness.
	Confirmed by: CT scan: no signs of ↑intracranial. pressure and LP: ↑lymphocytes in viral, ↑neutrophils in bacterial with organisms on staining and culture.
	Management: OHCM pp370–1.
Haemorrhagic stroke	Suggested by: sudden onset of headache, hemiparesis, sparing of upper face, dysarthia ± dysphasia, extensor plantar response.
	Confirmed by: CT brain scan: high attenuation area representing haemorrhage.
	Management: OHCM pp354–8.
Severe hypertension	Suggested by: continuous throbbing headache (non-severe hypertension is usually asymptomatic) but headache ± visual disturbance in malignant hypertension.
	Confirmed by: serial BP measurement: usually >140mmHg diastolic and/or >240mmHg systolic.
	Management: OHCM pp140–2.
Epilepsy	Suggested by: aura, altered consciousness, abnormal movements.
	Confirmed by: EEG result: spikes and waves over focus.
	Management: OHCM p380.
Acute glaucoma	Suggested by: blurred vision, painful red eye, coloured haloes.
	Confirmed by: ↑intraocular pressure on measurement.
	Management: OHCM p430.
Addison's disease	Suggested by: lethargy, weakness, dizziness, pigmentation (buccal, scar), hypotension.
	Confirmed by: 9 a.m. plasma cortisol ↓ and impaired response to short ACTH stimulation test (short Synacthen test).
	Management: OHCM p312.