The majority of patients were male (67%) and the mean age was 40.9 years. The proportion who smoke increased as APD increased (27% ≤1 up to 33% >3) and patients with comorbid depression almost doubled (11% ≤1 to 20% >3 APD).  Patients experienced a mean of 2.6 cluster periods per year which lasted an average of 30.8 days with a mean of 2.4 APD.  Three in ten patients had their CH condition misdiagnosed at least once prior to a confirmed CH diagnosis, most commonly being mislabelled with migraine (70%) or tension headache (22%). Most frequent current symptoms were unilateral pain (69%), orbital pain (46%), lacrimation (46%), conjunctival injection (43%) and temporal pain (41%). Symptoms were similar vs. APD. Patients reported feelings of stress (46%), anxiety (45%) and agitation (45%) being most prevalent during a typical attack, which increased proportionally as APD increased, and 67% described the level of pain suffered during a typical CH attack as severe to very severe. Reported findings were generally consistent across geographies.