1. ACUTE
1.1. Vascular
1.1.1. Ischaemic
1.1.2. Haemorrhagic
1.1.2.1. SAH
1.1.2.1.1. Thunderclap HA
1.1.2.1.2. altered GCS
1.1.3. Venous
1.2. Infection
1.2.1. Encephalitis
1.2.1.1. Seizure
1.2.2. Meningitis
1.2.2.1. Neck stiffness
1.2.2.2. Rash
1.2.2.3. Fever
1.2.2.4. Photophobia
1.2.3. Abscess
1.3. Compression
1.3.1. Obstructive Hydrocephalus (tumour)
1.3.2. Pituitary Enlargement (apoplexy)
1.4. ICP
1.4.1. Spontaneous intracranial hypotension
1.5. Opthalmic
1.5.1. Acute Glaucoma
1.5.1.1. Red eye
1.5.1.2. vomiting
1.5.1.3. misty vision
1.5.1.4. fixed dilated pupil
1.6. Unknown
1.6.1. Situational (Intercourse, Cough, Exertion)
1.7. Systemic
1.7.1. HTN
1.7.1.1. Phae
1.7.2. Infection
1.7.2.1. Sinusitis
1.7.3. Toxins
1.7.3.1. CO
2. CHRONIC
2.1. Migraine
2.1.1. unilateral, dull and throbbing
2.1.2. 4-72h
2.1.3. n & v, photophobia, phonophobia
2.1.4. prodromal sy
2.1.5. aura
2.2. Cluster HA
2.2.1. rapid onset, unilateral peri orbital
2.2.2. ptosis and lacrimation
2.2.3. 15min-3h, occur in clusters
2.3. Drugs
2.3.1. Vasodilators: Ca2+ antagonists, nitrates
2.3.2. Caffeine
2.3.3. Analgesia
2.4. Tension HA
2.4.1. Constant HA, head squeezed by vice
2.4.2. 4-6h
2.4.3. precipitated by stress
2.5. ICP
2.5.1. ↑: tumour, aneurysm, AVM, benign intracranial HTN
2.5.1.1. dull, throbbing
2.5.1.2. worse in AM (may wake up)
2.5.1.3. worse on coughing, relieved by standing
2.5.2. ↓: spontaneous intracranial hypotension
2.6. Neuralgia (trigeminal)
2.6.1. unilateral facial pain, stabbing electric shocks
2.6.2. triggered by area on face
2.7. Giant Cell Arthitis
2.7.1. Scalp tenderness, jaw claudication
2.7.2. blurred vision
2.8. Systemic
2.8.1. HTN
2.8.2. Organ Failure: Uraemia