Objective: To determine the development and outcome of chronic daily headache in 258 headache practice patients, consisting of 50 men and 208 women. Chronic daily headache was defined as headaches occurring on at least 5 days per week for at least 1 year.
Methods: Two hundred fifty-eight patients with headache were interviewed and evaluated. Ninety-one patients were contacted by telephone for follow-up.
Results: Twenty-two percent of the patients had daily headaches from the onset, and 78% initially experienced intermittent headaches. Of the patients with initially intermittent headaches, 19% experienced an abrupt transition into daily headaches and 81%, a gradual one. In the patients with gradual transition, the transition of the initial, intermittent headaches into daily headaches took an average of 10.7 years. The initial headaches were mild in 33% of the patients and severe in 67%. The severe headaches were associated with nausea and vomiting significantly more often than the mild ones. However, the daily headaches that these patients ultimately developed were the same, regardless of whether the initial headaches were mild or severe. The patients who gradually developed daily headaches from initially intermittent headaches were contacted to determine the outcome of their headaches. Of these patients, 33% continued to have daily headaches and 67% again experienced intermittent headaches. Of the latter group, 88% of the patients who now had migraine also had migraine initially.