Jaundice in adults happens when a yellow pigment called bilirubin builds up in the blood faster than the body can remove it. The yellowing typically becomes visible in the skin and whites of the eyes once bilirubin levels rise above 2.5 to 3 mg/dL, roughly two to three times the normal range. The causes fall into three broad categories depending on where the problem occurs: before the liver, inside the liver, or in the bile ducts leading away from it.
How Bilirubin Builds Up
Your body constantly recycles old red blood cells. About 70% of bilirubin comes from breaking down hemoglobin released by red blood cells that have reached the end of their roughly 120-day lifespan. Another 20% comes from the breakdown of other blood-related proteins in the liver, and the remaining 10% from red blood cells that never fully matured in the bone marrow.
Once released, bilirubin hitches a ride on a protein called albumin to travel through the bloodstream to the liver. There, the liver converts it into a water-soluble form (a process called conjugation) so it can be dissolved into bile. That bile flows through a network of ducts into the intestine, where bacteria break bilirubin down further into the pigments that give stool its brown color and urine its yellow color. A problem at any point in this chain raises bilirubin levels and produces jaundice.
Blood Disorders That Overwhelm the Liver
When red blood cells are destroyed faster than normal, the liver simply can’t keep up with the flood of bilirubin. This is the most common “pre-hepatic” cause of jaundice, and it’s driven by a group of conditions called hemolytic anemias.
Several inherited blood disorders cause this kind of accelerated breakdown. Sickle cell disease produces abnormally shaped red blood cells that get trapped and destroyed in small blood vessels, the spleen, or the liver. Thalassemia leads to fragile, easily destroyed red blood cells. G6PD deficiency, a genetic enzyme disorder, leaves red blood cells vulnerable to destruction when exposed to certain infections or medications.
Hemolytic anemia can also be acquired. In autoimmune hemolytic anemia, the immune system mistakenly tags red blood cells as foreign invaders and produces antibodies that destroy them. Infections, certain medications, and even mechanical heart valves can trigger red blood cell destruction as well. In all these cases, the jaundice tends to be mild, and because the bilirubin hasn’t yet been processed by the liver, it’s the unconjugated form that rises in blood tests.
Liver Damage and Inflammation
The liver itself is the most common site of trouble. When liver cells are inflamed or damaged, they lose their ability to process bilirubin efficiently, and both conjugated and unconjugated bilirubin spill into the bloodstream.
Viral Hepatitis
Hepatitis A, B, C, and E all inflame the liver and can cause jaundice. Hepatitis A and E typically cause a sudden, short-lived illness. Hepatitis B and C can become chronic infections that gradually scar the liver over years, with jaundice appearing during flare-ups or once significant damage has accumulated.
Alcohol-Related Liver Disease
Heavy drinking is one of the most common causes of jaundice in adults. Alcoholic hepatitis, a specific form of liver inflammation, is diagnosed when jaundice appears within eight weeks in someone who has been drinking heavily for at least six months. The threshold is roughly three or more standard drinks daily for women and four or more for men. The condition can range from mild to life-threatening, and bilirubin levels above 3 mg/dL are part of the diagnostic criteria.
Long-term alcohol use can also lead to cirrhosis, where healthy liver tissue is replaced by scar tissue. Once cirrhosis is advanced, the liver’s processing capacity drops permanently, and jaundice becomes persistent rather than episodic.
Drug-Induced Liver Injury
A surprisingly long list of medications and supplements can damage the liver enough to cause jaundice. Common over-the-counter pain relievers, including acetaminophen (Tylenol), ibuprofen (Advil, Motrin), and naproxen (Aleve), can all cause liver injury, particularly at high doses or with prolonged use. Acetaminophen overdose is one of the leading causes of acute liver failure in the United States.
Prescription medications linked to liver damage include statins for cholesterol, the antibiotic combination amoxicillin-clavulanate (Augmentin), the seizure medication phenytoin, the immunosuppressant azathioprine, certain antifungals, some antivirals, and anabolic steroids. Herbal supplements are a growing concern as well. Kava, comfrey, black cohosh, chaparral, cascara, ephedra, and even aloe vera taken orally have all been associated with liver toxicity.
Gilbert Syndrome
Not all liver-related jaundice is dangerous. Gilbert syndrome is the most common inherited disorder of bilirubin processing, affecting an estimated 6 to 14 percent of the population. People with this condition have lower levels of the enzyme responsible for conjugating bilirubin. Their eyes or skin may turn slightly yellow during periods of fasting, stress, illness, or intense exercise. It’s harmless, requires no treatment, and is often discovered incidentally on a routine blood test.
Blocked Bile Ducts
Even when the liver processes bilirubin perfectly, jaundice can develop if the bile carrying it can’t reach the intestine. This is called obstructive or “post-hepatic” jaundice, and it produces a distinctive set of symptoms: dark tea-colored urine, pale or clay-colored stools, and often intense itching as bile salts accumulate under the skin.
Gallstones are the most common culprit. Roughly 5 in 1,000 people develop gallstones that migrate out of the gallbladder and lodge in the bile duct, blocking the flow of bile. This usually causes sudden, severe pain in the upper right abdomen along with rapid-onset jaundice.
Tumors of the pancreas, bile duct, or the area where the bile duct meets the intestine can also obstruct bile flow. Pancreatic cancer, in particular, often presents with painless jaundice because the tumor presses on the bile duct as it grows. Bile duct strictures, which are areas of abnormal narrowing caused by previous surgery, chronic inflammation, or scarring from infections (including certain parasitic infections), are another cause. These tend to develop gradually, with jaundice worsening slowly over weeks.
How Doctors Identify the Cause
When you show up with yellow eyes or skin, the first step is a blood test measuring total bilirubin and its two forms: conjugated and unconjugated. This single test narrows the field significantly. If unconjugated bilirubin is elevated, the problem is likely happening before the liver, either from excessive red blood cell breakdown or a processing issue like Gilbert syndrome. If conjugated bilirubin is high, the issue is in the liver itself or in the bile ducts downstream.
Liver enzyme patterns provide the next layer of information. Doctors compare levels of two key enzymes to calculate a ratio that classifies the injury pattern as either primarily cell damage (pointing toward hepatitis, drugs, or alcohol) or primarily bile flow obstruction (pointing toward gallstones or tumors). In alcohol-related liver disease specifically, about 90% of patients show a characteristic pattern where one liver enzyme is more than double the other, a useful clue when the cause isn’t immediately obvious.
Imaging usually follows. An ultrasound can quickly reveal gallstones, dilated bile ducts, or masses. If a blockage is suspected but not clearly seen, more detailed imaging with CT, MRI, or a specialized scope procedure can map the bile ducts and identify the exact location and nature of the obstruction.
Patterns Worth Recognizing
The speed at which jaundice develops and the symptoms that accompany it often point toward the cause. Sudden jaundice with fever and abdominal pain suggests an acute process like a gallstone blocking a bile duct or acute hepatitis. Gradual, painless jaundice that deepens over weeks raises concern for a tumor compressing the bile duct. Jaundice that comes and goes mildly with stress or illness, especially in a young adult with no other symptoms, is often Gilbert syndrome.
Pale stools and dark urine together strongly suggest a bile duct blockage, because bilirubin can’t reach the intestine to be converted into the pigments that color stool, and instead backs up into the blood and spills into urine. Jaundice paired with signs of chronic liver disease, such as spider-like blood vessels on the skin, fluid buildup in the abdomen, or easy bruising, points toward cirrhosis from alcohol, chronic hepatitis, or another long-standing liver condition.