The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had a profound global impact on public health. Patients with chronic conditions such as type 2 diabetes mellitus (T2DM) are particularly vulnerable to severe COVID-19 outcomes. T2DM is characterized by chronic hyperglycemia, insulin resistance, and systemic inflammation, which impair the immune response and increase susceptibility to infections and their complications. In patients with T2DM and COVID-19, significant metabolic and inflammatory disturbances are frequently observed. Hyperglycemia and insulin resistance are exacerbated by the infection, leading to poor glycemic control and elevated levels of glycated hemoglobin (HbA1c). The inflammatory processes induced by COVID-19 result in increased levels of CRP, IL-6, and other inflammatory markers, indicating systemic inflammation that correlates with disease severity. A comprehensive understanding of the impact of COVID-19 on patients with T2DM and their laboratory parameters is crucial for developing effective treatment strategies and improving outcomes. Intensive glycemic control, management of inflammatory and coagulation processes, and monitoring of liver and kidney functions are key aspects of treating these patients. These measures can significantly reduce the risk of severe complications and mortality, enhancing the quality of life and prognosis for patients with T2DM during the COVID-19 pandemic.