Hepatitis B virus dna quantification below the lower limit of detection is contagious, just very low. Hepatitis B virus DNA quantification is the most central indicator of viral activity, and a value below the lower limit of detection indicates that the hepatitis B virus is replicating slowly. However, because hepatitis B is currently a disease that cannot be completely cured, although the DNA quantification test is lower than the lower limit, but the patient still has a small amount of hepatitis B virus in the body, still infectious, but very low infectious. Generally speaking, as long as the surface antigen of hepatitis B shows positive, it will be infectious. Patients suffering from hepatitis B should go to regular hospitals for examination, and if antiviral treatment is needed according to the examination results, use entecavir tablets, tibivudine tablets, tenofovir tablets and other medicines as prescribed by the doctor, and do not use medicines on your own in order to avoid adverse consequences. At the same time, patients with hepatitis B should pay attention to rest, avoid staying up late, eat a light diet, more protein, vitamins and other nutrients.