An emerging disease refers to a new or previously unrecognized disease that increases in incidence or geographic range. These diseases can arise from factors such as genetic mutations, environmental changes, increased human-animal interactions, or global travel, leading to new pathogens or amplified transmission rates. Emerging diseases can pose significant health challenges, impacting public health systems and requiring ongoing research to understand their mechanisms, prevention strategies, and treatment options. Notable examples include COVID-19 and HIV/AIDS.