Primary headaches and characteristics
| Types | Characteristics |
| Migraine | Unilateral location, pulsating quality, moderate or severe intensity, aggravation by routine physical activity, association with nausea and/or photophobia and phonophobia, lasting from 4 to 72 hours. |
| Tension-type headache | Bilateral, pressing or tightening in quality and mild-to-moderate intensity, lasting from 30 min to 7 days. |
| Cluster headache | Severe in intensity, strictly unilateral to the orbital, supraorbital and temporal area or in any combination of these sites, lasting 15–180 min and occurring from once every other day to eight times a day. |