Hepatitis B Surface antigen (HBsAg)

HBsAg positive means current hepatitis B infection. Many adults clear it, but persistence over six months indicates chronic infection, raising risks of cirrhosis and liver cancer. Severity varies—some have mild disease, others need antiviral therapy and lifelong monitoring (ALT, HBV DNA and liver imaging). Close contacts require testing and vaccination. See a clinician for staging and treatment decisions.

A positive hepatitis B surface antigen (HBsAg) means hepatitis B virus is present in the blood, indicating an active infection that can be transmitted to others. It may reflect acute or chronic infection; persistence beyond six months usually denotes chronic disease. Additional tests (HBV DNA, anti‑HBc IgM/total, liver function tests) define stage and treatment need. Medical follow-up and contacts’ testing/vaccination are recommended.

HBsAg (hepatitis B surface antigen) should be negative/non-reactive. Most labs report non-reactive when HBsAg is below the assay cutoff (commonly an index <1 or a quantitative value <0.05 IU/mL), though exact cutoffs vary by test. A positive/reactive HBsAg indicates current hepatitis B infection and warrants further evaluation. Discuss any results with your clinician.

Yes. Being HBsAg‑positive does not bar marriage. Partners should be informed; test the partner for HBV and vaccinate if non‑immune. Use condoms until immunity is confirmed. Medical care may include antiviral therapy (if high viral load) and, for pregnant women, steps to prevent mother‑to‑child transmission (newborn vaccine plus HBIG). With counseling, treatment and vaccination, transmission risk is greatly reduced.

HBsAg-positive patients should be evaluated for chronic hepatitis B with HBV DNA, liver enzymes and fibrosis assessment. For those meeting treatment criteria, first-line antiviral therapy is oral tenofovir (TDF or TAF) or entecavir; pegylated interferon is an alternative in select cases. Lifelong antiviral suppression may be required; regular monitoring and specialist (hepatology/infectious disease) follow-up are recommended.

The four stages of hepatitis B are: incubation — virus replicates without symptoms for weeks to months; acute — symptomatic illness (fever, malaise, jaundice) lasting weeks; chronic — infection persisting beyond six months, ranging from inactive carrier to active liver inflammation; and recovery/carrier — either resolution with immunity or an inactive carrier state with low-level virus and possible future reactivation.