Asymptomatic means having a disease or infection without showing noticeable symptoms. A person can be asymptomatic while still being infected and potentially contagious to others. This concept became widely known during the COVID-19 pandemic, when many infected individuals spread the virus without knowing they were sick because they felt fine. Asymptomatic transmission complicates disease control because people who feel healthy may not take precautions or seek testing. Public health strategies like widespread testing and masking help address asymptomatic spread by protecting against transmission from people who do not know they are infected.