Cranial Causes
Migraine Tension Headache Cluster Headache Hemicrania Raised ICP
Vascular Causes
Subdural Haemorrhage Extradural Haemorrhage SAH GCA (temporal arteritis) Venous Thrombosis
Infectious Causes
Meningitis
Encephalitis
Neuro Causes
Trigeminal Neuralgia
Iatrogenic Causes
Painkiller Overuse
Caffeine/alcohol
ENT
Sinusitis
Other
Acute Glaucoma
TMJ dysfunction
Bedside
Urine dip (blood in hypertensive encephalopathy) Throat swab: meningitis
Bloods
FBC, UEs, LFTs, CRP, ESR
Cultures and meningococcal PCR
LP
Meningitis
12 hours post SAH if CT head normal
Imaging
CT head: bleed
MRI: thrombus (angiography)
CXR: pneumonia
Special Test
GCA - temporal artery biopsy
Tonometry - measure ocular pressure in acute glaucoma