Distinguishing between the three main types of primary headaches is crucial for selecting appropriate targeted therapies
| Clinical Feature | Migraine | Tension-Type Headache (TTH) | Cluster Headache |
| Pain Localization | Unilateral (often bilateral in some cases) | Bilateral | Unilateral (strictly one-sided) |
| Pain Quality | Pulsating, throbbing | Pressing, tightening, non-pulsating | Severe, deep, excruciating |
| Pain Severity | Moderate to severe | Mild to moderate (not disabling) | Very severe |
| Physical Activity | Aggravated by routine physical activity (leads to avoidance) | Unaffected by routine physical activity | Causes restlessness/agitation |
| Associated Features | Nausea, vomiting, photophobia, phonophobia | Absence of severe nausea or sensory phobias | Ipsilateral autonomic signs (lacrimation, nasal congestion, ptosis, eyelid edema) |
| Duration & Frequency | 4 to 72 hours per attack; 1–2 times per month | Hours to days | 15 to 180 minutes per attack; 1–8 attacks per day during active bouts |
Understanding these phenotypic signatures ensures rapid diagnostic accuracy at the bedside.