RESUMO
Chronic daily headaches (CDH) is a descriptive term used for patients who experience headaches on at least 15 days or more out of the month; for at least 3 months, irrespective of the underlying headache etiology. It is a syndrome that affects many people, usually with an underlying primary headache disorder, leading to a reduction in quality of life. The two most common underlying primary headaches are migraines and tension-type headaches. The prevalence is about 4%, and research is emerging on risk factors and comorbidities. The first step when approaching a patient with chronic daily headaches is to rule out secondary causes. Once that is done, the goal is to effectively reduce the days of headache through preventive treatment as well as complementary therapies. This also often involves limiting the use of abortive therapy to avoid medication-overuse headaches (MOH). The pathophysiology, although not fully understood, is thought to be related to central sensitization along with "neurogenic inflammation." Chronic daily headaches can be difficult to treat and at times require a tertiary specialized center.