Hepatitis B is caused by?

Hepatitis B is caused by a virus, specifically the Hepatitis B virus (HBV). This virus is a member of the Hepadnaviridae family and is characterized by its ability to infect liver cells, leading to inflammation and a variety of clinical outcomes including acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma.

The transmission of Hepatitis B occurs primarily through exposure to infectious body fluids, such as blood, semen, and vaginal secretions, making it a viral infection rather than one caused by bacteria, parasites, or fungi. Understanding that Hepatitis B is a viral infection emphasizes the necessity of vaccination and antiviral treatments, which are critical for managing and preventing the spread of the virus.