Jaundice is the visible yellowing of the skin, eyes, and mucous membranes that occurs when bilirubin, a yellow pigment produced during the normal breakdown of red blood cells, builds up in the bloodstream. It is not a disease in its own right but a sign that something has gone wrong with the body’s ability to process or eliminate bilirubin. The causes range from harmless and self-limiting to life-threatening, and the treatment depends entirely on which part of that processing chain has broken down.
Where Bilirubin Comes From and Where It Goes
Your body continuously recycles old red blood cells. When one reaches the end of its roughly 120-day lifespan, it is broken down, and the hemoglobin inside it is converted into bilirubin by an enzyme in the liver, spleen, and bone marrow. This “unconjugated” bilirubin travels through the bloodstream bound to a protein called albumin and arrives at the liver, where a second enzyme transforms it into a water-soluble “conjugated” form that can be excreted into bile. The bile flows into the intestines, giving stool its characteristic brown color, and a small amount is filtered out by the kidneys into the urine. Jaundice appears whenever bilirubin production outpaces the body’s ability to conjugate and excrete it, or when something physically blocks bile from draining.
That single conjugation enzyme in the liver, known as UGT1A1, is the only enzyme that substantially contributes to bilirubin processing.1PubMed. The genetic basis of the reduced expression of bilirubin UDP-glucuronosyltransferase 1 in Gilbert’s syndrome This is why jaundice can result from so many different problems: anything that overwhelms UGT1A1 with too much bilirubin, damages the liver cells that house it, or blocks the bile ducts that carry conjugated bilirubin away will cause levels to rise.
The Three Categories of Causes
Doctors group the causes of jaundice by where the problem occurs relative to the liver. This classification is practical because it guides which tests to order and which treatments to consider.
Pre-Hepatic Causes
When red blood cells are destroyed faster than normal, the sheer volume of bilirubin overwhelms the liver’s processing capacity. The result is a rise in unconjugated bilirubin. Hemolytic anemias, in which the immune system attacks red blood cells, inherited red-cell disorders like sickle cell disease and thalassemia, and transfusion reactions can all trigger this. In newborns, hemolytic causes are significant and often underrecognized contributors to dangerous bilirubin levels, with both immune-mediated and non-immune conditions in the mix.2PubMed Central. Neonatal Hemolytic Jaundice: Causes, Diagnostic Approach, and Management A blood-type mismatch between mother and baby is a classic example.
Hepatic Causes
When the liver itself is damaged or inflamed, its cells lose the ability to conjugate and excrete bilirubin efficiently. Viral hepatitis (A, B, C, and E), alcoholic liver disease, drug-induced liver injury, and autoimmune hepatitis all fall into this category. One reassuring quirk: after an acute bout of hepatitis from a virus, drug, or toxin, jaundice can persist for weeks or even months during recovery, long after the initial insult has resolved. As alarming as this looks, liver enzymes typically trend downward and the liver’s synthetic function stays intact, distinguishing this prolonged but benign convalescent phase from progressive liver failure.3PubMed Central. Prolonged Direct Hyperbilirubinemia Following Acute Hepatitis: When Not to Worry? – Section: Abstract
A separate pattern of hepatic jaundice comes from cholestasis, where bile flow within the liver is impaired even though the large bile ducts outside the liver remain open. Primary biliary cholangitis is a well-known example: it is an autoimmune liver disease in which the immune system targets the small bile ducts inside the liver, causing progressive cholestasis and potentially cirrhosis over time.4PubMed. Primary biliary cholangitis: a comprehensive overview Certain medications and pregnancy can also cause intrahepatic cholestasis.
Post-Hepatic (Obstructive) Causes
When something physically blocks the bile ducts after they leave the liver, conjugated bilirubin backs up into the bloodstream. Gallstones lodged in the common bile duct are the most common benign cause, while cancers of the pancreatic head, bile duct (cholangiocarcinoma), gallbladder, and ampulla are the most worrisome. In obstructive jaundice from malignancy, the yellowing tends to be persistent and progressive, whereas gallstone-related jaundice often fluctuates.5PubMed Central. The clinical efficacy and safety of different biliary drainages in malignant obstructive jaundice treatment One study of patients admitted with biliary obstruction found that about two-thirds had a malignant cause, with pancreatic cancer being the single most common, while gallstones accounted for the majority of benign cases.6PubMed. Fate of patients with obstructive jaundice
Jaundice in Newborns
Newborn jaundice is so common it is practically expected. Most infants develop what is called physiological jaundice, a harmless spike in unconjugated bilirubin that appears between 24 and 72 hours after birth, peaks around the fourth or fifth day in full-term babies (later in preterm infants), and fades by about two weeks. Bilirubin levels during this window usually stay under about 15 mg/dL, and current guidelines accept levels up to roughly 17–18 mg/dL in otherwise healthy term newborns.7PubMed Central. Hyperbilirubinemia in Neonates: Types, Causes, Clinical Examinations, Preventive Measures and Treatments: A Narrative Review Article – Section: Physiological Jaundice
The reason nearly every newborn gets at least a touch of jaundice is straightforward: babies are born with more red blood cells than they need for life outside the womb, those cells have a shorter lifespan, and the infant liver has not yet ramped up UGT1A1 expression enough to keep pace. Human infants develop hyperbilirubinemia specifically because of this inadequate UGT1A1 expression in the liver.8PubMed Central. Importance of UDP-glucuronosyltransferase 1A1 expression in skin and its induction by UVB in neonatal hyperbilirubinemia Breastfeeding jaundice, caused partly by mild dehydration and reduced stool output in the early days, can push levels higher but is generally managed by increasing feeding frequency.
Pathological jaundice in newborns is a different story. It appears within the first 24 hours of life, rises rapidly, or reaches dangerously high levels. If unconjugated bilirubin climbs high enough, it can cross the blood-brain barrier and deposit in the basal ganglia and brainstem, causing a permanent condition called kernicterus. The neurological damage from kernicterus includes a specific form of cerebral palsy, hearing loss, and problems with eye movement.9PubMed Central. Kernicterus This is why hospitals screen bilirubin levels before discharge and why parents are told to watch for deepening yellow color in the first week.
Symptoms Beyond Yellow Skin
The hallmark sign is yellowing that typically shows up first in the whites of the eyes (the sclera) and then spreads to the face, chest, and rest of the body as bilirubin levels climb. This scleral yellowing is important diagnostically because it helps distinguish true jaundice from other conditions that can make skin look yellow.
Other symptoms depend on the underlying cause but commonly include:
- Dark urine: when conjugated bilirubin enters the bloodstream in excess, the kidneys filter some of it out, turning urine tea-colored or brown.
- Pale stools: if bile cannot reach the intestines (as in obstructive jaundice), stools lose their brown pigment and become clay-colored or chalky white.
- Itching: cholestatic jaundice in particular often causes maddening itching (pruritus), which can be the most debilitating symptom for people with chronic liver disease.
- Fatigue and abdominal pain: hepatitis-related jaundice often comes with right-upper-quadrant discomfort, nausea, and exhaustion.
- Fever: suggests an infectious cause such as cholangitis (infected bile ducts) or viral hepatitis.
The combination of pale stools and dark urine with jaundice is a strong indicator that the problem is obstructive rather than hemolytic, since in hemolytic jaundice the liver is still excreting bile normally and stool color stays unchanged.
How Jaundice Is Diagnosed
A blood test measuring total and direct (conjugated) bilirubin is the first step. If most of the bilirubin is unconjugated, the problem is likely pre-hepatic or related to impaired conjugation. If it is predominantly conjugated, the issue is in the liver or bile ducts. But bilirubin alone does not tell the whole story: it does not always point to a liver lesion, so doctors assess it alongside the patient’s history, the degree of elevation, and the pattern of other lab abnormalities such as liver enzymes and alkaline phosphatase.10PubMed Central. Measurement and clinical usefulness of bilirubin in liver disease
When obstructive jaundice is suspected, imaging is essential. Ultrasound is usually the first-line scan because it is fast, cheap, and good at detecting dilated bile ducts and gallstones. If more detail is needed, two advanced imaging options are available: endoscopic ultrasound (EUS) and magnetic resonance cholangiopancreatography (MRCP). A Cochrane review found that both have excellent accuracy for detecting common bile duct stones, with no statistically significant difference between them.11PubMed Central. Endoscopic ultrasound versus magnetic resonance cholangiopancreatography for common bile duct stones A separate meta-analysis of head-to-head studies found a slight edge for EUS in sensitivity.12PubMed. Diagnostic accuracy of EUS compared with MRCP in detecting choledocholithiasis: a meta-analysis of diagnostic test accuracy in head-to-head studies In practice, availability and the patient’s ability to undergo sedation often determine which is used.
Treatment Depends on the Cause
Because jaundice is a symptom rather than a disease, there is no single treatment. The strategy is to identify and address whatever is producing the excess bilirubin or preventing its clearance.
Phototherapy for Newborns
For neonatal jaundice that crosses treatment thresholds, phototherapy remains the standard of care. The baby is placed under special lights that convert unconjugated bilirubin in the skin into water-soluble forms the body can excrete without needing conjugation by the liver. This approach, first described about 60 years ago, has been credited with saving millions of infants from death and disability.13PubMed. Sixty years of phototherapy for neonatal jaundice – from serendipitous observation to standardized treatment and rescue for millions Research into optimizing the light wavelength continues: one study found that blue-green LED light at around 478 nanometers was about 31% more efficient at clearing bilirubin than standard blue LED light at around 452 nanometers.14PubMed Central. Blue-Green (~480 nm) versus Blue (~460 nm) Light for Newborn Phototherapy-Safety Considerations In severe cases that do not respond to phototherapy, exchange transfusion, where the baby’s blood is partially replaced, is used to prevent kernicterus.
Treating Liver Disease
When jaundice stems from hepatitis or other liver inflammation, treating the underlying cause is the priority. Antiviral medications for hepatitis B or C, stopping the offending drug in drug-induced liver injury, or immunosuppressive therapy for autoimmune hepatitis can all resolve jaundice as the liver heals. For hepatitis B-related acute-on-chronic liver failure with severe jaundice, antiviral therapy is initiated immediately, and some studies have explored adding glucocorticoids, though outcomes for that combination are still being evaluated.15PubMed Central. Efficacy of glucocorticoid therapy for severe jaundice patients with drug-induced liver injury or hepatitis B virus-related acute-on-chronic liver failure: a respectively observational study
Relieving Bile Duct Obstruction
Gallstones blocking the common bile duct are typically removed through a procedure called ERCP (endoscopic retrograde cholangiopancreatography), where a scope is passed through the mouth into the duodenum and the stone is extracted. For malignant obstruction that cannot be surgically cured, palliative biliary stenting has become the go-to approach. Endoscopic stent placement effectively relieves jaundice and improves liver function with fewer complications than surgery, successfully draining bile in more than 80% of cases.16PubMed Central. Endoscopic stent placement in the palliation of malignant biliary obstruction When endoscopic access is not feasible, an alternative is percutaneous transhepatic drainage, where a tube is placed through the skin directly into the bile ducts. Both approaches achieve similar success rates in relieving jaundice, though ERCP tends to cause fewer complications.5PubMed Central. The clinical efficacy and safety of different biliary drainages in malignant obstructive jaundice treatment
Gilbert’s Syndrome and Other Genetic Causes
Not all jaundice signals something dangerous. Gilbert’s syndrome is a common hereditary condition marked by mild, intermittent increases in unconjugated bilirubin that are entirely benign.17PubMed Central. Gilbert’s syndrome: The good, the bad and the ugly It affects roughly 5–10% of the population in many ethnic groups and is caused by a variation in the promoter region of the UGT1A1 gene that reduces the enzyme’s activity.1PubMed. The genetic basis of the reduced expression of bilirubin UDP-glucuronosyltransferase 1 in Gilbert’s syndrome People with Gilbert’s syndrome may notice their eyes turn slightly yellow during fasting, stress, illness, or heavy exercise, and it resolves on its own. No treatment is needed.
At the more severe end of the spectrum sits Crigler-Najjar syndrome, a rare genetic disorder in which UGT1A1 activity is profoundly reduced (type 2) or absent (type 1). Genetic testing is reserved for distinguishing Gilbert’s syndrome from Crigler-Najjar type 2 when bilirubin levels are much higher, generally above about 6 mg/dL, because the distinction matters for family counseling and medication safety.18Journal of Hepatology. Gilbert’s syndrome revisited – Section: Diagnosis of Gilbert’s syndrome People with Gilbert’s syndrome do need to be aware that certain drugs metabolized by UGT1A1, including the chemotherapy agent irinotecan, can build up to toxic levels in their system.
When Yellow Skin Is Not Jaundice at All
A surprisingly common reason for yellow skin that turns out not to be jaundice is carotenemia. If you eat large amounts of carrots, sweet potatoes, squash, or other carotene-rich foods, the pigment can accumulate in your skin and give it a distinctly yellow-orange hue. The telltale difference is that carotenemia does not affect the sclera: the whites of the eyes stay white.19PubMed Central. Carotenemia: A Case Report Babies starting on pureed vegetables are common culprits, as are adults who go heavy on juicing. No treatment is needed beyond adjusting the diet.
Other conditions that can mimic jaundice include the use of certain medications (like rifampin, which can tint tears and skin orange) and chronic kidney disease, which sometimes gives skin a yellowish cast from retained urochrome pigments. Checking the eyes is the simplest bedside way to tell these apart from true jaundice.
The Itch That Comes with Cholestatic Jaundice
For many people living with chronic cholestatic liver diseases like primary biliary cholangitis or primary sclerosing cholangitis, the worst symptom is not the yellowing but the relentless itching. Cholestatic pruritus can be severe enough to interfere with sleep and daily functioning. Current guideline-recommended therapies often fall short in moderate to severe cases, which has driven interest in newer drug classes. Recently approved inhibitors of a bile acid transporter in the intestine (called IBAT inhibitors) and emerging activators of certain nuclear receptors (PPAR agonists) are showing promise, and patients with refractory itching may benefit from referral to clinical trials testing these agents.20Current Hepatology Reports. Cholestatic Pruritus: Pathophysiology, Current Management Approach, and Emerging Therapies
Herbal Supplements as an Underappreciated Risk
One cause of jaundice that catches many people off guard is liver injury from herbal and dietary supplements. Because these products are sold without prescriptions, they are widely assumed to be safe, but supplement-induced liver injury now accounts for about 20% of hepatotoxicity cases in the United States based on research data.21PubMed Central. Liver injury from herbal and dietary supplements Green tea extract is a well-documented offender, but the majority of cases now involve multi-ingredient nutritional supplements in which the toxic component is unknown or can only be suspected. The rise in supplement use over recent decades has been accompanied by a parallel increase in reports of supplement-associated liver damage.22PubMed Central. Herbal and Dietary Supplement-Induced Liver Injury
If you develop jaundice and are taking any over-the-counter supplements, bodybuilding products, weight-loss aids, or herbal remedies, mention them to your doctor. Clinicians may not think to ask about supplements the way they ask about prescription medications, and the omission can delay diagnosis. Stopping the offending product is usually the most important step in recovery.