Our study also revealed that patients with older age, male gender, risky occupations, fever, headache, muscle ache, dyspnea, diarrhea, associated comorbidities (diabetes mellitus, hypertension, heart disease, and bronchial asthma), lower platelets, lymphocytes, and absolute lymphocyte count, and higher NLR, PLR, CRP, ferritin, LDH, and D dimer were related to the severity of COVID-19. This evidence concerns the gene CRP and diabetes mellitus.