By definition, chronic daily headaches occur 15 or more days per month for at least 3 months. But, as the name suggests, some headache patients suffer almost daily with headaches.
Risk factors for developing CDH:
- Previous history of frequent headaches
- History of minor head trauma
- Association with psychiatric disorders, such as depression and anxiety
- Major life changes
- Sleep changes
CDH does not fit into any specific criteria, but the major primary headaches can become CDH. These include:
- Chronic migraine (CM)
- Chronic tension-type headache (CTTH)
- New daily persistent headache (NDPH)
- Hemicrania continua
- Medication overuse headache (MOH)
Chronic migraine Patients who suffer from episodic migraine can develop chronic migraines, where the headaches occur for more than 8 days per month. The other characteristics of the pain and associated symptoms are similar to the episodic migraine.