hi,welcome to HCM liver function tests include(1).liver enzymes(ast,alt and alkaline phosphatase) which have specific range and function (2)bilirubin levels (total,conjugated and unconjugated which reflects pre hepatic i.e.blood lysis.hepatic-liver damage or post hepatic _obstruction to bile ) depending on which we diagnose jaundice and types if positive.. (3)proteins (albumin ,globulin and ratio )which reflects synthetic function of liver ... liver impairment is caused by various factors (toxins,infection,obstruction,alcohol,tumours,portal hypertension etc..) the normal levels may vary from person to person.. do you have any symotoms like pain abdomen,yellowish dark urine,yellowish conjuctiva,itching etc we should know which of these values are elevated and by how much... for healthy liver avoid alcohol,smoking,control diabetes,hypertension,get hepatitis vaccinated,eat healthy balanced diet,avoid infections... consult a gastroenterogist or physician and follow their advice.. stay fit bye