Defined as presence of headache more than 15 days per month for longer than 3 months.
Additionally defined as daily headache with at least two of the following characteristics: unilateral location, pulsating quality, moderate or severe pain intensity, aggravation by routine physical activity.
It must also include at least one of the following: nausea/vomiting, photophobia, pain relieved by triptan or ergot, and no other explanation such as medication overuse or other cause.
Refers to a number of primary and secondary disorders.
Primary headaches refer to migraine, tension type, and cluster headaches.
Secondary causes of chronic headaches include infection, anatomical abnormalities such as Chiari malformation, infections, neoplasms, and high or low cerebrospinal fluid pressure.
Classified on the basis of length of episodes with brief ref2242ing to headaches lasting less than 4 hours and prolonged being 4 hours or more.
Transformed migraine and medication overuse headaches are the most common types.
Transformed migraine and drug overuse headaches most commonly in women and in patients with episodic migraines dating back to childhood or adolescence.
Approximately 3-5% of population worldwide and 70-80% of patients presenting to a headache clinic in the U.S. have such headaches.
Leads to impaired physical, social, mental and occupational functioning.
Risk factors include obesity, caffeine consumption, overuse of analgesics including ergots and triptans.
Over half of patients have sleep problems, depression and anxiety.