**2. Pathophysiology**

The pathophysiology of hepatic encephalopathy is intricate and exact mechanisms leading to HE are not clearly understood. Hepatic encephalopathy pathogenesis has many components which include ammonia, inflammatory cytokines, benzodiazepine like compounds and manganese like substances which impair neuronal function.(9) The role of ammonia has dominated explanations for the pathogenesis of HE but it cannot single handedly explain all the neurological changes seen in HE. Evidence regarding other concurrent factors has emerged over the years and it is thought that these factors either work alone or in synergy to cause astrocytes to swell and fluid to accumulate in brain which causes the symptoms of HE(10). Some factors and conditions also appear to precipitate HE (Box A).
