Background: The COVID-19 pandemic caused serious health problems that affected people physically, and psychologically around the globe. This study aimed to (1) understand physical distress (PhD), psychological distress (PsD), and coping experiences among people infected with COVID-19 (2) develop a grounded theory (3) examine PhD, PsD, and coping among people infected with COVID-19. Methods: A sequential exploratory mixed methods strategy was employed. A qualitative procedure was based on a grounded theory, data collection included observation and in-depth interviews with 25 participants, aged 18 years and above. The quantitative one included 180 participants, from Bangkok Metropolitan, and Northeastern region of Thailand from February to May 2022. A snowball sampling technique was used. Quantitative instrument: was built based on grounded data from a qualitative approach. Physical, psychological distress, and coping were assessed. Content analysis was applied using the Strauss and Corbin method, and software ATLAS.ti. Descriptive statistic, Pearson’s correlation, and independent t-test were used. Results: Six major themes included 10 sub-themes. The six major themes appeared (1) severity of COVID-19 symptoms (2) death anxiety (3) uncertainty (4) barrier to healthcare access (5) compliance, and self-regulation coping (6) post-COVID-19 effects. PhD, PsD, and coping were at a moderate level. All PhD, PsD, and coping were in positive relations. Comparison of PsD, and coping between the non-severe group and severe group was significantly different (p<0.001, p<0.05). Post COVID-19 effects were fatigue, dyspnea, high blood sugar level, impairment of lungs, liver, and kidney. Conclusions: The findings of the study supported 6 major themes including 10 sub-themes. All PhD, PsD, and coping were in positive relations. The PsD, and coping of the severe group was higher than non-severe group. Suggestions, healthcare providers should be concerned with sufficient healthcare services, physical and psychological supports. The interventions are needed for their recovery from physical and psychological effects.