- Have underlying cause
- Medication overuse, arteritis, ↑ICP, infection.
High risk (investigate further)
- Sudden-onset headache (max intensity in 1 min)
- Worsening headache with fever
- New-onset neurological deficit
- New-onset cognitive dysfunction
- Change in personality
- Impaired level of consciousness
- Recent (3 months) head trauma
- Headache triggered by cough, valsalva
- Headache triggered by exercise
- Orthostatic headache (changes with posture)
- Symptoms suggestive of giant cell arteritis
- Symptoms and signs of acute narrow-angle glaucoma
- Substantial change in the characteristics of their headache.
- Compromised immunity
- Hx malignancy
- Vomiting without other obvious cause.
- ↑ICP (E.g SOL - neuros signs, papilloedema)
- Venous thrombosis (papilloedema)
- Glaucoma - headache, blurred vision, vomiting, dusky cornea (recent halos), semi dilated pupil (constricted in cluster)
- Cluster bouts
- Temporal arteritis - jaw claudication, new headache, myalgia, ±tender temporal art, ↑ESR, ±PMR ("roll" out of bed).
- Optic neuritis may present with retro-orbital pain with eye movement.
|Headache feature||Tension-type headache||Migraine (with or without aura)||Cluster headache|
|Pain location 1||Bilateral||Unilateral or bilateral||Unilateral (around the eye, above the eye and along the side of the head/face)|
|Pain quality||Pressing / tightening (non-pulsating)||Pulsating (throbbing or banging in young people aged 12–17 years)||Variable (can be sharp, boring, burning, throbbing or tightening)|
|Pain intensity||Mild or moderate||Moderate or severe||Severe or very severe|
|Effect on activities||Not aggravated by routine activities of daily living||Aggravated by, or causes avoidance of, routine activities of daily living||Restlessness or agitation|
|Other symptoms||None||Unusual sensitivity to light and/or sound or nausea and/or vomiting Aura Symptoms can occur with or without headache and:
||On the same side as the headache:
|Duration of headache||30 minutes–continuous||4–72 hours in adults 1–72 hours in young people aged 12–17 years||15–180 minutes|
|Frequency of headache||< 15 days per month||≥ 15 days per month for more than 3 months||< 15 days per month||≥ 15 days per month for more than 3 months||1 every other day to 8 per day, with remission> 1 month||1 every other day to 8 per day, with a continuous remission4<1 month in a 12-month period|
|Diagnosis||Episodic tension-type headache||Chronic tension-type headache 2||Episodic migraine (with or without aura)||Chronic migraine (with or without aura)||Episodic cluster headache||Chronic cluster headache|
|1. Headache pain can be felt in the head, face or neck. 2. Chronic migraine and chronic tension-type headache commonly overlap. If there are any features of migraine, diagnose chronic migraine.|
Ottawa SAH rule
The ottawa SAH rule has a 100% sensitivity (but low specificity) for SAH. A patient with headache does not require investigations if then do not have any of:
- age ≥40 years.
- neck pain or stiffness.
- witnessed loss of consciousness.
- onset during exertion.
- thunderclap headache [instantly peaking pain].
- limited neck flexion on examination.