Jaundice is extremely common in newborns and relatively common in adults with liver or blood disorders. About 50% of full-term newborns and 80% of premature babies develop visible yellowing of the skin in their first week of life. In adults, jaundice is not a disease itself but a visible sign that something is interfering with how the body processes bilirubin, a yellow pigment produced when red blood cells break down.
Newborn Jaundice by the Numbers
Half of all babies born at full term will turn noticeably yellow within a few days of birth. For premature infants, that number jumps to roughly 80%. In most cases, this is harmless. A newborn’s liver is still maturing and can’t clear bilirubin as efficiently as an older child’s or adult’s liver. The yellowing typically starts on the face and head, then spreads downward toward the chest, belly, and eventually the arms and legs as bilirubin levels rise.
Jaundice becomes visible when total bilirubin levels exceed about 3 mg/dL in the blood. Most healthy newborns see their levels peak around day three to five and then gradually decline without treatment. When levels climb high enough to need intervention, the standard treatment is phototherapy, where the baby is placed under special blue-spectrum lights that help break down bilirubin in the skin. The American Academy of Pediatrics updated its guidelines in 2022 with slightly raised thresholds for starting phototherapy, reflecting newer safety data.
Why Breastfed Babies Are More Likely to Turn Yellow
There are actually two distinct forms of jaundice linked to breastfeeding, and they happen at different times for different reasons. The first, sometimes called breastfeeding jaundice, occurs in the first few days when a baby isn’t getting enough milk yet. Fewer feedings mean fewer bowel movements, and bilirubin that would normally leave the body through stool gets reabsorbed instead.
The second type, breast milk jaundice, shows up later (usually after the first week) and affects about one-third of exclusively breastfed newborns. Certain compounds in breast milk appear to slow the liver’s processing of bilirubin. This form is almost always mild, can last several weeks, and rarely requires any change in feeding. In both cases, continuing to breastfeed is generally recommended.
Severe Jaundice Varies Dramatically by Region
While mild newborn jaundice is harmless, severely elevated bilirubin can damage the brain if left untreated. The global burden is strikingly uneven. In sub-Saharan Africa, the incidence of severe neonatal jaundice is roughly 668 per 10,000 live births, according to a systematic review from the University of Minnesota. In the Americas and Europe, the rate drops to between 3.7 and 4.4 per 10,000. That gap reflects differences in access to screening, phototherapy equipment, and timely medical care rather than any biological difference in how often jaundice occurs.
Visual assessment of skin color is the most accessible screening tool in low-resource settings, but its reliability is limited. The standard method involves checking five body zones from head to feet, with deeper progression suggesting higher bilirubin. Research from Tanzania found this approach missed a large proportion of cases in dark-skinned newborns, detecting only about 17% of babies with elevated bilirubin in one South African study. Blood or skin-based bilirubin measurements remain far more accurate.
How Common Is Jaundice in Adults?
There’s no single prevalence figure for adult jaundice because it’s a symptom, not a diagnosis. It shows up across a wide range of conditions, and how common it is depends entirely on the underlying cause. The most frequent triggers are hepatitis (especially viral hepatitis), alcohol-related liver disease, bile duct blockages from gallstones or tumors, and toxic reactions to medications or herbal supplements.
Age shapes the pattern. In younger, otherwise healthy adults, acute viral hepatitis is the most common reason for new-onset jaundice. In older adults, a blocked bile duct is more likely, and cancer becomes an increasingly important cause of that blockage. Drug-induced liver injury is another significant contributor at any age, with certain antibiotics, anti-seizure medications, and even herbal products like green tea extract and kava among the known culprits.
Some people carry a genetic variation called Gilbert syndrome that causes occasional mild jaundice, particularly during fasting, stress, or illness. It affects roughly 3% to 7% of the population and is considered benign. Rarer inherited conditions like Dubin-Johnson syndrome can also cause intermittent yellowing but are far less common.
What Jaundice Looks and Feels Like
The hallmark sign is yellowing of the skin and the whites of the eyes. In lighter skin tones, this is usually obvious. In darker skin tones, the yellowing is easiest to spot in the eyes, the palms of the hands, and the soles of the feet. Newborns may also appear sleepy, feed poorly, or have dark yellow urine and pale stools when bilirubin levels are significantly elevated.
In adults, jaundice often comes with other symptoms tied to its cause: itching (common with bile duct blockages), fatigue, abdominal pain, dark urine, or pale clay-colored stools. The yellowing itself isn’t painful, but it’s a signal that something in the liver, bile ducts, or blood is off. Adults who notice new yellowing of their skin or eyes can expect their doctor to order blood tests measuring bilirubin levels along with liver function, and possibly imaging of the liver and bile ducts to identify the source.
Who’s at Higher Risk
Several factors increase the likelihood of jaundice across different age groups:
- Premature birth: Preterm infants have the least mature livers and the highest rates of jaundice at 80%.
- Blood type incompatibility: When a mother and baby have different blood types, the baby’s red blood cells can break down faster than normal, flooding the system with bilirubin.
- Exclusive breastfeeding: About a third of breastfed newborns develop breast milk jaundice, though it’s almost always mild.
- Heavy alcohol use: Chronic alcohol consumption is one of the leading causes of liver disease and adult jaundice worldwide.
- Hepatitis exposure: Viral hepatitis, particularly hepatitis B and C, remains a major global cause of jaundice in adults, especially in regions with limited vaccination coverage.
- Medication use: Certain prescription drugs and herbal supplements can stress the liver enough to trigger visible jaundice.
For newborns, jaundice that appears within the first 24 hours of life, rises rapidly, or persists beyond two weeks warrants closer evaluation. For adults, any visible yellowing of the skin or eyes is worth investigating, since the causes range from easily treatable (a gallstone) to serious (liver disease or cancer) and early identification changes outcomes significantly.