Purpose : This study aimed to verify that adenoid hypertrophy (AH) and rhinosinusitis share similar epidemiologic patterns and that AH and allergic rhinitis (AR) are not related. Methods: Internet search engine query data from January 2011 to December 2019 were retrieved from the Baidu index. Monthly search volume was obtained in China for the following search terms in Chinese: “adenoid hypertrophy,” “rhinosinusitis,” and “allergic rhinitis”; the data obtained were then presented as percentages. Pearson’s and Spearman’ s correlation coefficients were used to detect the correlation among the search volumes of AH, rhinosinusitis, and AR. We also collected search data from the first 5 months of 2020, when segregation was implemented in China due to the coronavirus disease 2019 epidemic. Then, we compared the search data to those obtained during the same period in 2019 to detect the effects of segregation on AH and AR to varying degrees. Results: Statistically significant differences were found between the search variations of AH and rhinosinusitis during 2011–2019 (R=0.643, P<0.05). However, search variations of AH and AR were negatively related (R=-0.239, P<0.05). The average monthly search volume of AH and rhinosinusitis correlated well (R=0.836, P<0.01), but no correlation was found between AH and AR. The search volume of AH and rhinosinusitis during the first 5 months in 2020 decreased, whereas that of AR increased during January–February. Conclusions: AH and rhinosinusitis are epidemiologically related, whereas AH and AR are not correlated with each other.