In this study, with the aim of obtaining basic data for proposing odor countermeasures suitable for each department, we examined odor characteristics by patient characteristics using data from a questionnaire survey on odors conducted in hospitals nationwide. As a result, it was found that the timing of odor generation and the type of odor differ depending on patient characteristics, and that in addition to excretory odors generated at specific times, body odor and halitosis, which are always perceived, have an impact on the odor environment.In addition, patient characteristics of each department were identified.