COVID‐19 is highly transmissible; however, its severity varies from one individual to another. Variability among different isolates of the virus and among its receptor (ACE2) may contribute to this severity, but comorbidity plays a major role on disease prognosis. Many comorbidities have been reported to be associated with severe COVID‐19 patients. We have collected data from retrospective studies which include clinical and epidemiological features of patients and categorize them into severe/mild, ICU/non‐ICU and survivors/dead patients. In this review, we give an update about SARS‐CoV‐2 structure with emphasis on the possible reasons for the severity of the virus in patients. We also collected information and patients’ data to highlight the relation between COVID‐19 patients and comorbidities.