A positive nucleic acid test is an indicator of a confirmed diagnosis. The carrier of genetic information in viruses, bacteria or other pathogens is the nucleic acid gene, which is not the same in different viruses and bacteria. A positive nucleic acid test can be a confirmation of the diagnosis because the detection of nucleic acid in human specimens, such as blood, sputum, or ascites or pleural fluid (fluid that stays in the chest cavity), indicates that the pathogen is already present in the body. In the case of novel coronaviruses, a positive nucleic acid test is a confirmatory indicator of the diagnosis. For other viruses, such as Hepatitis B virus and Hepatitis C virus, a positive test for nucleic acid in the blood can also confirm Hepatitis B virus infection or Hepatitis C virus infection, which are all important evidence for diagnosis. A positive nucleic acid test is a confirmation of the diagnosis. After the diagnosis is confirmed, symptomatic supportive treatment is needed. In some cases, antiviral therapy is required, and life care should be intensified.