• Patients with obstructive jaundice that can be treated surgically or endoscopically should be promptly identified. Upper abdominal ultrasonography should be performed urgently on acutely icteric patients.
• Investigations are performed to disclose whether jaundice due to hepatic cell damage is associated with acute or chronic liver disease.
• Haemolysis (Haemolytic anaemia) should be diagnosed.
• True icterus should be differentiated from Gilbert's syndrome (Gilbert's syndrome) and from hypercarotinaemia that is found in patients who eat a lot of carrots.

• Jaundice is observed in the skin or sclerae, or plasma bilirubin is > 40 .

Haemolysis or Gilbert's syndrome

• The bilirubin is unconjugated (total bilirubin is increased, conjugated bilirubin is not). Results of other liver function tests (ALT, ALP) are normal.

Parenchymal jaundice

• The concentration of conjugated bilirubin is increased.
• Acute jaundice
  • Acute viral hepatitis
  • Drug-induced hepatitis or by herbal products
  • Right-sided heart failure
  • Postoperative jaundice
  • Sepsis
  • Intravenous nutrition
• Chronic jaundice
  • Alcoholic hepatitis
  • Cirrhosis of the liver
  • Autoimmune hepatitis
  • Chronic viral hepatitis (HBV, HCV)
  • Hepatoma
  • Intrahepatic cholangiocarcinoma
  • Liver metastases

Obstructive jaundice

• Common bile duct stone
• Cholecystitis
• Carcinoma of the pancreas
• Cholangiocarcinoma of the extrahepatic bile ducts
• Acute or chronic pancreatitis
• Spasm of sphincter of Oddi
• Postoperative stricture of the biliary ducts

Icterus due to hypercarotinemia

• There is no icterus on the sclerae.
• Liver function tests are normal; usually a history and normal physical findings are sufficient for making the diagnosis.

• Duration of the jaundice
• Itch (suggestive of obstruction or intrahepatic cholestasis)
• Abdominal pain (common in obstruction but may also occur in alcoholic hepatitis)
• Cholecystectomy
• Loss of appetite (viral hepatitis)
• Loss of weight (malignancies)
• Travel abroad, contact with an icteric patient, transfusions
• Drugs
• Consumption of alcohol; ask the patient's family or friends, too.

• Tenderness (cholecystitis)
• Liver size (enlarged liver – alcoholic fatty liver, hepatitis, tumour)
• Consistency of the liver
• Signs of portal hypertension: spider naevi, palmar erythema, gynaecomastia, splenomegaly, ascites
• Palpable, untender gallbladder (carcinoma of the pancreas)
• Injection scars

• An acutely jaundiced patient should be referred to hospital for the following morning. If obstructive icterus lasts for more than three weeks a permanent liver damage results. The obstruction should be relieved before that.
• Ultrasonography can differentiate obstructive jaundice from parenchymal jaundice: the intrahepatic bile ducts are usually dilated in obstructive jaundice, although they may be normal during the first few days. Gallbladder stones, cholecystitis, and hepatic metastases can be visualized.

• Basic blood count with platelets, CRP, bilirubin, conjugated bilirubin, ALT, AST, alkaline phosphatase, GGT, plasma or urine amylase, plasma albumin, prothrombin time or INR
• If the infrahepatic bile ducts are not dilated and the cause of jaundice is not clear after the aforementioned investigations, examine the following:
  • to disclose alcoholic aetiology: plasma ethanol, blood PEth
  • to disclose haemolysis: blood reticulocyte count, plasma lactate dehydrogenase and haptoglobin concentrations, Coombs’ test
    • Especially when other liver function tests are normal
  • to disclose autoimmune liver diseases: plasma IgG, IgA, IgM, antinuclear antibodies (ANA), anti-smooth muscle antibodies, antimitochondrial antibodies
  • to disclose viral hepatitis: HAV-IgM antibodies, HBV surface antigen (HBsAg), HCV antibodies, CMV nucleic acid, EBV nucleic acid and, if necessary, HEV antibodies.
• Other aetiology – rare reasons of chronic icterus, investigations based on consideration:
  • Haemochromatosis: ferritin, transferrin saturation
  • Wilson’s disease: copper, caeruloplasmin
  • Alpha-1-antitrypsin deficiency: alpha-1-antitrypsin
• Interpretation
  • Alkaline phosphatase > 150 U/l suggests obstructive jaundice.
  • Increased MCV, increased GGT/alkaline phosphatase ratio, increased AST/ALT ratio, increased IgA or blood PEth or positive plasma ethanol suggest alcoholic liver disease.
  • Decreased plasma albumin or increased INR suggest parenchymal disease.

• MRI cholangiography is the method for screening the cause of obstruction before ERCP if the pretest probability of gallstones is low or moderate.
• Endoscopic retrograde cholangiography (ERCP) is the best investigation for finding out the location and type of obstruction. If needed, the obstruction can be alleviated by extraction of stone or by stenting the malignant stricture.
• Doppler ultrasonography (changes or obstruction of flow in the portal vein and hepatic veins), CT or MRI are performed in special cases (haemochromatosis, tumours)
• Liver biopsy is the best method to investigate the aetiology, severity and prognosis of chronic liver disease (liver enzyme concentrations increased > 6 months).