The role of negative affectivity on patients' perceptions of and behav
ior during asthma attacks was explored among 47 asthmatic subjects. Pa
tients completed 17 to 30 daily questionnaires assessing negative affe
ct, asthma perception, additional drug intake, search for medical assi
stance, and peak-flow measures of respiratory distress. Asthma percept
ions were correlated with negative affect and educational level; the p
erception of the asthma severity, but not negative affect, did predict
behavior during an attack. The importance of symptom perceptions for
the clinical management of chronic asthma is underscored.