Chronic hepatitis refers to acute hepatitis B and acute hepatitis C that cannot be cured for a long time and lasts for more than half a year, and then turns into chronic hepatitis. There are also many cases of chronic hepatitis where many people are infected with the hepatitis virus and the onset of the disease is hidden. When it is discovered, it has already become chronic hepatitis. Chronic hepatitis is highly contagious. Hepatitis A and hepatitis E generally do not develop into chronic hepatitis, but acute hepatitis A has the phenomenon of being lingering and not being cured. Hepatitis D can only occur at the same time as hepatitis B or when the patient is already carrying the hepatitis B virus, because the hepatitis D virus is a defective virus that must rely on the hepatitis B virus to reproduce and spread. Hepatitis D can also turn into chronic hepatitis.