Introduction: This study aims to determine differences between the number of underlying medical conditions, depression, and anxiety, when controlling for the covariates of age, sex, and completed education. Methods: Participants (n = 484) indicated the number of medical conditions present during the survey, also including the PHQ-9 and GAD-7, to assess depression and anxiety, respectively. Results: Differences were found between groups of medical conditions and the combined values of PHQ-9 and GAD-7 after controlling for the covariates mentioned above (F4,954 = 5.78; Wilks’ Λ=0.95; P< 0.0005). The univariate tests showed differences for PHQ-9 (F2,478 = 8.70; P< 0.0005) and GAD-7 (F2,478 = 11.16; P< 0.0005) between the 3 groups. Finally, post-hoc analysis showed differences between participants with one medical condition and with no medical condition (PHQ-9: MD = 1.82; 95%CI, 0.25-3.40; GAD-7: MD = 1.73; 95%CI, 0.55-2.91), and between participants with more than one medical condition and participants with no medical condition (PHQ-9: MD = 3.10; 95%CI, 1.11-5.10; GAD-7: MD = 2.46; 95%CI, 0.97-3.95). Conclusions: Our results suggest that people who had a medical condition during the COVID-19 pandemic were more prone to developing severe symptoms of anxiety and depression.