Neonatal jaundice may have first been described in a Chinese textbook 1000 years ago. Neonatal jaundice affects one in two infants globally, neonatal jaundice (NNJ) is a common condition worldwide occurring in up to 60% of term and 80% of preterm newborns in the first week of life.The term ?jaundice? is used to describe the yellow-orange discoloration of the skin and sclera because of excessive bilirubin in the skin and mucous membranes. Jaundice itself is not a disease but rather a symptom or sign of a disease. The jaundice is the result of an accumulation of bilirubin as foetal haemoglobin is metabolised by the immature liver. Jaundice can be broadly classified as pre-hepatic, hepatic or post-hepatic/cholestatic.
Hyperbilirubinemia is the commonest morbidity in the neonatal period and 5-10% of all newborns require intervention for pathological jaundice. Misdiagnosis of cholestasis as physiologic jaundice in early identification, reinforcing the need to test for the condition at 2 to 3 weeks of age in jaundiced infants, and to provide an approach to investigation.
Physiologic jaundice is an unconjugated hyperbilirubinemia that occurs after the first postnatal day and can last up to 1 week. Total serum bilirubin (TSB) concentrations peak in the first 3 to 5 postnatal days and decline to adult values over the next several weeks. Physiological jaundice may be exacerbated by the following: polycythaemia, extravasated blood, delayed passage of meconium, sallowed blood, hypocaloric feed intake, dehydration, breast feeding and prematurity.
Pathologic hyperbilirubinemia in a newborn can be separated into four categories: increased bilirubin production, deficiency of hepatic uptake, impaired conjugation of bilirubin, and increased enterohepatic circulation. Pathologic  jaundice conjugated hyperbilirubinemia is a conjugated bilirubin concentration greater than 1 mg/dl (17.1 ?mol/l) when the TSB concentration is 5 mg/dl (85.6 ?mol/l) or less. if the TSB concentration is greater than 5 mg/dL (85.6 ?mol/L), conjugated hyperbilirubinemia is defined when the value is 20% or greater of the TSB concentration. In an infant older than 3 weeks of age, total and conjugated bilirubin should be measured to rule out cholestasis and biliary atresia, which are associated with elevated conjugated bilirubin concentrations.
Prolonged jaundice beyond 3 weeks is defined as persistence of significant jaundice (10 mg/dl) beyond three weeks in a term baby. The common causes include breast milk jaundice, extravasated blood (cephalhematoma), ongoing hemolytic disease, G-6PD deficiency and hypothyroidism. Up to 15% of breastfed infants experience jaundice lasting more than 3 weeks meanwhile, neonatal cholestasis occurs in 0.04% to 0.2% of live births. 
Early identification of cholestatic jaundice to enable optimal timing of medical and surgical management can be achieved through universal assessment of infants at 2 weeks of age, measurement of direct reacting bilirubin levels in any who appear jaundiced, and immediate referral to pediatric liver services if cholestasis is identified.
Cholestatic jaundice is always pathologic and indicates hepatobiliary dysfunction. Early detection by the primary care physician and timely referrals to the pediatric gastroenterologist/hepatologist are important contributors to optimal treatment and prognosis. The most common causes of cholestatic jaundice in the first months of life are biliary atresia (25%?40%) followed by an expanding list of monogenic disorders (25%), along with many unknown or multifactorial (eg, parenteral nutrition-related) causes, each of which may have time-sensitive and distinct treatment plans. Cholestasis can be classified into biliary (obstructive, large extrahepatic, or small intrahepatic bile ducts) or hepatocellular (defect in membrane transport, embryogenesis, or metabolic dysfunction) in origin The differential diagnoses include a variety of anatomic, infectious, autoimmune, genetic, metabolic, and congenital conditions.
The minimum evaluation for any health care professional encountering an infant with jaundice present after the age of 14 days should include a full history including family history and gestational history of the mother, physical examination, inspection of stool color, and obtaining a fractionated bilirubin measurement. When cholestasis is suspected, expedited focused investigations are recommended.
Jaundice management depends on the etiology obtained as: breast milk jaundice a mothers should be advised to continue breast-feeding, interruption of breast-feeding is not recommended unless TSB level exceeds 20 mg/dl. Biliary atresia need a protoenterostomy. 
In conclusion jaundice in early identification is very important present after the age of 14 days for investigations, management to optimal treatment and prognosis for outcome pathological jaundice.