Chronic migraine as a disease was initially recognized in patients with a large burden of disability from frequent headaches and a history of prior migraines. Over time, this observation was operationalized into multiple diagnostic criteria with requirements for frequent headache days, typically 15 or more, which, on at least 8 days in a month, have the features of migraine headache. Chronic migraine affects 1-2% of the general population, and about 8% of patients with migraine. Understanding disease mechanisms still remains a challenge. Inflammation and central sensitization play significant role in the evolutive mechanisms of chronic migraine. Treatment of this condition should primarily focus on the prevention. The currently available evidence-based prophylactic treatment options are topiramate, valproic acid, onabotulinumtoxin A and recently developed promising anti-CGRP monoclonal antibodies. Chronic migraine research is a dynamic and rapidly advancing area. New developments in this field have the potential to improve the diagnosis, to provide more personalized treatments and to reduce burden of disability.