Viremia is a medical condition in which a virus is present in the bloodstream of an infected person or animal. This occurs when a virus invades the body and replicates within host cells, leading to the release of viral particles into the bloodstream. Viremia can occur during the early stages of infection and can last for varying amounts of time depending on the virus and the immune response of the infected individual. Viremia can also increase the risk of transmission of the virus to other individuals, as the virus is present in the bloodstream and can be spread through bodily fluids. Viremia can be detected through laboratory testing, such as a viral load test or PCR test.