Symptoms are those of severe acute liver injury, usually with a prodromal period of fatigue, nausea, poor appetite and right upper quadrant discomfort followed by dark urine and jaundice followed by signs or symptoms of hepatic failure.  The diagnosis of acute liver failure is actually based upon the appearance of clinical symptoms of hepatic encephalopathy, such as mental clouding, confusion, asterixis, somnolence, stupor and coma.  Other features of liver failure include abdominal swelling due to ascites, peripheral edema and coagulopathy.  The rapidity of onset of the symptoms of hepatic encephalopathy varies greatly.  Cases in which symptoms of encephalopathy arise within days of onset of hepatitis are usually referred to as "hyperacute", within 5 days to 8 weeks of onset as "acute", and after 8 weeks of onset as "subacute".  Initial symptoms of hepatic encephalopathy may be subtle and include a change in personality, forgetfulness, reversal of day-night pattern of wakefulness, and irrational or violent behavior.