This assignment provides a comprehensive overview of Hepatitis B Virus (HBV), a life-threatening viral infection affecting the liver. It defines HBV according to the World Health Organization, detailing its transmission, taxonomic classification, and associated signs and symptoms such as jaundice, fever, and fatigue. The assignment explores the common causes of HBV, including unprotected sex, contact with infected fluids, and mother-to-child transmission. It also covers diagnostic methods like liver ultrasounds and blood tests, including HBsAg, Anti-HBs, and Anti-HBc tests. Treatment options, ranging from immunoglobin injections to antiviral medications and liver transplants, are discussed. The assignment concludes with HBV's epidemiology, highlighting global infection rates, chronic cases, and mortality statistics, including data for the United States. References from WHO, CDC, and other relevant sources are included.