A 61-year-old female had a wellness checkup that included a CBC. Three weeks later, she encountered someone who later tested positive for COVID-19. Five days later, she began developing some common symptoms, such as cough, fever, and fatigue. She had relatively minor signs for one week, but then she developed shortness of breath; her oxygen saturation decreased, and she was admitted to the hospital. A CBC was done upon admission and is shown below compared to her CBC at the wellness visit. The reference range is listed in the last column.
| Wellness Visit | Admission | Reference Range |
| Hgb | 13.8 g/dL | 13.5g/dL | 12-16 g/dL |
| HCT | 41% | 41.2% | 37-47% |
| RBC | 4.8 x 106/μL | 4.7 x 106/μL | 4.2-5.4 x 106/μL |
| WBC | 6.7 x 103/μL | 8.4 x 103/μL | 4.8-10.8 x 103/μL |
| platelets | 240,000/μL | 222,400/μL | 150,000-400,000/μL |
| Neutrophils | 3.9 x 103/μL | 6.2 x 103/μL | 1.5-6.5 x 103/μL |
| Lymphocytes | 1.9 x 103/μL | 1.8 x 103/μL | 1.2-3.4 x 103/μL |
| Monocytes | 0.28 x 103/μL | 0.35x 103/μL | 0.11-0.59 x 103/μL |
| Eosinophils | 0.1 x 103/μL | 0.06 x 103/μL | 0-0.5 x 103/μL |
| Basophils | 0.6 x 103/μL | 0.1 x 103/μL | 0-0.2 x 103/μL |
