Figure 2. D-dimer, a COVID-19 inflammatory marker, trended throughout hospitalization. X-axis represents hospital days from day 1, the first day of hospitalization, to day 18, day of hospital discharge. D-dimer was trended approximately once every 2 days; therefore, aside from days 1 and 2 and days 10 to 12, which represent 24-h time frames, all other data points are approximately 48 h apart in the patient’s hospital course. Y-axis is representative of D-dimer values in ng/mL obtained throughout hospitalization. Values are listed in 1000 ng/mL increments. Day 10 (arrow), represented on the X-axis, demonstrates the day the patient’s D-dimer rose significantly and peaked at 6840 ng/mL, as represented on the Y-axis. Close monitoring of the D-dimer trend and observation of its peak on day 10 led to further investigation with computed tomography angiography, which ultimately led to the discovery of a new aortic free-floating thrombus.