Types of Headaches in Adults
Adult patients with headache history can experience primary headaches (migraine, tension-type, cluster, and other primary headache disorders) or secondary headaches (caused by underlying medical conditions), with approximately 90% of people experiencing headache during their lifetime. 1
Primary Headache Disorders
Primary headaches are unrelated to underlying medical conditions and represent the vast majority of headache presentations. 1
Migraine
Migraine without aura is the most common migraine subtype and requires: 2
- At least 5 attacks lasting 4-72 hours untreated
- At least two of: unilateral location, pulsating quality, moderate-to-severe intensity, or aggravation by routine physical activity (walking, climbing stairs)
- At least one of: nausea/vomiting OR both photophobia and phonophobia
- Affects approximately 12% of the population and is the most disabling primary headache 1
Migraine with aura presents with: 2
- At least 2 attacks with fully reversible aura symptoms (visual, sensory, speech/language, motor, brainstem, or retinal)
- Aura symptoms spreading gradually over ≥5 minutes
- Individual aura symptoms lasting 5-60 minutes
- Aura accompanied by or followed by headache within 60 minutes
Chronic migraine is diagnosed when: 2, 3
- Headache occurs on ≥15 days/month for >3 months
- On ≥8 days/month for >3 months, the headache meets criteria for migraine or responds to triptan/ergot treatment
- This represents transformation from episodic to chronic pattern
Tension-Type Headache
Tension-type headache affects 38% of the population and is characterized by: 4, 3, 1
- Bilateral pressing/tightening (non-pulsating) character
- Mild-to-moderate intensity
- Not aggravated by routine physical activity
- No nausea/vomiting AND no more than one of photophobia or phonophobia
- This is the most prevalent primary headache but less disabling than migraine 1, 5
Cluster Headache
Cluster headache requires: 3
- Five attacks with severe unilateral orbital/supraorbital/temporal pain
- Duration of 15-180 minutes untreated
- Frequency of one to eight attacks daily
- At least one ipsilateral autonomic symptom (lacrimation, nasal congestion, eyelid edema, miosis/ptosis)
Other Primary Headache Disorders
This category includes less common primary headaches that don't fit the above classifications. 1
Secondary Headache Disorders
Secondary headaches result from underlying medical conditions and are classified by etiology. 1
Medication-Overuse Headache
This is a critical secondary headache that develops from the treatment of primary headaches: 2, 3, 6
- Headache on ≥15 days/month in someone with pre-existing headache disorder
- Regular overuse for >3 months of acute medications:
- Non-opioid analgesics on ≥15 days/month for ≥3 months, OR
- Any other acute medication or combination on ≥10 days/month for ≥3 months
- Represents central sensitization and transformation to chronic intractable headache 7
Common pitfall: Patients often fail to report over-the-counter analgesics or substances obtained from others, making medication history crucial. 7, 8
Other Secondary Causes
Secondary headaches can be due to: 4, 1
- Vascular causes: Cerebral venous thrombosis (especially with cancer or hypercoagulable states), spontaneous intracranial hypotension (improves lying flat, worsens upright)
- Neoplastic causes: Intracranial mass lesions, tumors, arteriovenous malformations
- Increased intracranial pressure: Pseudotumor cerebri syndrome (particularly in overweight females with papilledema)
- Infectious causes
- Cervicogenic headache: Provoked by cervical movement rather than posture
Red Flag Features Requiring Urgent Evaluation
These features mandate immediate assessment for secondary causes: 4
- New onset headache in patients over 50 years of age
- Headache worsened by Valsalva maneuver or cough
- Headache that awakens patient from sleep
- Abnormal neurological examination findings
- Abrupt onset ("thunderclap" pattern) 1
- Presence of cancer or immunosuppression 1
Diagnostic Approach
Medical history is the mainstay of diagnosis and must include: 2, 4
- Age at onset, duration, and frequency of episodes
- Pain characteristics: location, quality (pulsating vs. pressing), severity, aggravating/relieving factors
- Accompanying symptoms: photophobia, phonophobia, nausea, vomiting
- Aura symptoms if present
- Acute and preventive medication use history (including over-the-counter and substances from others) 7
- Orthostatic component (better lying down, worse upright) 4
Physical examination should include: 4
- Complete neurological examination
- Fundoscopy to check for papilledema
- Head and neck focused examination 7
Headache diaries are valuable diagnostic tools that document frequency, symptoms, triggers, and treatment response over time. 2, 4, 7
Key Classification Principles
The ICHD-3 classification is phenomenological, not etiological, meaning it classifies the headache as a clinical entity rather than the patient—one patient can have multiple simultaneous headache diagnoses. 3
Early presentations may not meet full diagnostic criteria and should be coded as "probable" subtypes until sufficient attacks occur to confirm the diagnosis. 2, 3
Common pitfall: Assuming chronic headache is always primary without considering secondary causes, particularly medication-overuse headache in patients on long-term analgesics. 8, 4