Which of the following complications is closely associated with severe COVID-19?

Severe COVID-19 is particularly associated with pneumonia due to the virus's primary impact on the respiratory system. COVID-19 can lead to acute respiratory distress syndrome (ARDS) and significant inflammation in the lungs, resulting in pneumonia, which is an infection or inflammation of the lung tissue. This condition complicates the disease progression and often requires medical intervention such as supplemental oxygen or mechanical ventilation.

While diabetes mellitus, cardiac arrhythmias, and neurological disorders can occur due to various health interactions with COVID-19, such associations are typically seen as secondary complications or outcomes rather than direct consequences of the primary viral infection. In contrast, pneumonia is a direct manifestation of the respiratory impairments caused by the virus, making it the most closely associated complication with severe cases of COVID-19.