“…The reported frequency of these symptoms in CF patients is very variable in the literature, although generally higher than the frequency in our study. Recent European and North American studies have shown that the symptoms most frequently associated with CF are coughing (in about 60%), 29 nasal block (in 60 to 90.5%), 3,29,45,46 rhinorrhea (in 20 to 85.7%), 3,29,36,45,46 headaches (in 22.6 to 71.4%), 3,29,46 facial pain (in 15 to 57.1%),45,46 and sleep disorders with agitation, snoring and daytime drowsiness (in 37%), especially in patients with severe nasal block.15 In Brazil, Boari and Castro Jr. 42 found that except for coughing, symptoms of rhinosinusitis occurred infrequently. These variations probably reflect the small samples and different age groups in these studies.…”