Newborn Jaundice: Normal, and When It Is Dangerous

In short

Around 60 percent of healthy newborns develop jaundice in the first days of life, and most cases resolve on their own within one to two weeks without treatment.
Jaundice appearing in the first 24 hours of life, or spreading to the legs and feet, always needs same-day medical assessment.
G6PD deficiency is common across the Arab world and can cause bilirubin to rise dangerously fast, narrowing the window for safe treatment.
Phototherapy is safe, effective and the standard treatment: it converts bilirubin in the skin into a form the body can excrete without relying on the liver.
Do not use direct sunlight as a substitute for medical phototherapy: it cannot deliver an adequate dose safely and risks burning a newborn's fragile skin.

What this article covers

What is jaundice and why does it happen in newborns?
Physiological jaundice versus pathological jaundice
Why G6PD deficiency raises the stakes in the Arab world
Warning signs that mean go to the emergency department now
How phototherapy works, and is it safe?
Does sunlight work instead of phototherapy?
Breast milk jaundice and breastfeeding jaundice: two different things
What to watch for after leaving hospital

What is jaundice and why does it happen in newborns?

Newborn jaundice is the yellow colouring of a baby's skin and the whites of the eyes. It is caused by a build-up of bilirubin, a yellow substance produced when red blood cells break down. The liver normally processes bilirubin and excretes it in bile, but a newborn's liver works slowly at first and cannot keep pace with the volume of bilirubin being produced as the extra red blood cells from the womb break down.

Around six in ten healthy, full-term newborns develop visible jaundice in their first days of life. In most of these cases the jaundice is mild, resolves on its own within one to two weeks as the liver matures, and requires no treatment beyond good feeding. The condition is so common that it has a name for this normal variant: physiological jaundice.

In a smaller proportion of cases, bilirubin climbs to levels that can cause permanent brain damage. The difference between these two situations is the timing, the speed of rise, and the distribution on the body, not simply the presence of yellow colouring. This is why knowing what to look for matters.

When jaundice appears and what it usually means

First 24 hours Early onset jaundice: always a medical emergency, assess immediately
Day 2 to 5 Physiological jaundice: normal in most healthy full-term newborns
Week 2 Jaundice begins fading in most infants
Beyond 2 weeks Prolonged jaundice: needs investigation to find the cause

Physiological jaundice versus pathological jaundice

Physiological jaundice is the normal form. It typically appears on day two or three of life, is confined to the face and chest, is mild, and fades gradually over one to two weeks. A baby with physiological jaundice feeds well, appears active, and has normal urine and stool colour. No treatment is usually needed beyond ensuring the baby feeds frequently.

Pathological jaundice departs from this pattern in one or more ways. It appears in the first 24 hours of life, or it is severe enough to spread to the abdomen, legs and feet, or it persists beyond two weeks in a full-term infant, or it is accompanied by pale stools, very dark urine, or a visibly unwell baby. Any of these patterns signals a problem that needs medical investigation.

A 2017 review in the British Journal of Hospital Medicine by Mitra and Rennie identified the most common causes of pathological jaundice: blood group incompatibility between mother and baby (ABO or Rh), G6PD deficiency, infection, and liver or bile duct problems. Each requires different management. Distinguishing them requires blood tests, which is why home observation has limits.

Physiological versus pathological jaundice

Feature	Physiological	Pathological
Onset	Day 2 to 3	Within 24 hours of birth
Distribution	Face and chest only	Spreads to abdomen and legs
Duration	7 to 14 days	Beyond 2 weeks
Baby's condition	Active, feeding well	Lethargic or poor feeder
Response needed	Monitoring, good feeding	Medical assessment the same day

Why G6PD deficiency raises the stakes in the Arab world

Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that protects red blood cells from destruction. When a newborn lacks sufficient G6PD, red blood cells break down much more rapidly than normal when triggered by certain stresses, releasing large amounts of bilirubin very quickly. This can drive bilirubin levels up dangerously fast.

G6PD deficiency is one of the most common inherited enzyme disorders in the world, and it is particularly prevalent across the Middle East, North Africa and the Mediterranean basin. A study published in the Journal of Pediatrics in 2015 examined Arab and Palestinian-Arab neonates and documented significant G6PD deficiency rates in these populations, underlining the clinical importance of screening in the region. An earlier study from Al Ain in the UAE found that G6PD deficiency was a significant driver of severe hyperbilirubinaemia in that population.

A 2022 review in Frontiers in Pediatrics described the mechanism in detail: G6PD-deficient red cells in a newborn are vulnerable to oxidative stress from infections, certain foods the breastfeeding mother ate, or naphthalene exposure from mothballs, causing haemolysis and a sudden spike in bilirubin. The problem is that this spike can happen within hours. Many families do not know they carry the trait until a baby is affected. If any family member is known to have G6PD deficiency, tell the maternity team at the time of delivery so the baby can be monitored closely from birth.

Warning signs that mean go to the emergency department now

Severe untreated hyperbilirubinaemia causes a condition called kernicterus, where bilirubin deposits in the brain and causes permanent damage including cerebral palsy, hearing loss and intellectual disability. Kernicterus is entirely preventable with timely intervention. The tragedy is that it still occurs when warning signs are missed or when families wait for a morning appointment.

Go to the emergency department the same day if you see any of the following: jaundice appearing in the first 24 hours of life; yellowing spreading to the legs and feet; the baby is very difficult to wake, or is limp; the baby refuses to feed at all; the baby has an unusually high-pitched cry that does not sound like normal crying; the baby arches their neck or back; or you see any twitching or seizure-like movements. Do not wait until morning.

How phototherapy works, and is it safe?

Phototherapy is the standard treatment for significant neonatal jaundice. The baby is placed under a bank of blue-spectrum lights, typically wavelengths between 430 and 490 nanometres. This light penetrates the skin and converts bilirubin molecules into a form that the body can excrete in urine and stool without the liver needing to process them first. It is a physical conversion, not a chemical treatment.

A 2023 Cochrane systematic review comparing continuous and intermittent phototherapy found both approaches effective at reducing bilirubin levels and confirmed the established safety profile of the intervention. Common temporary side effects include reddened skin, greenish stools and mild dehydration, all of which resolve when treatment stops. The baby's eyes are covered with protective shields during treatment, all clothing is removed to maximise skin exposure, and breastfeeding continues during short breaks.

Families sometimes worry about phototherapy because of the equipment and the need to stay in hospital. The reassurance is that the treatment itself is well tolerated by newborns and the alternative, untreated high bilirubin, is far more dangerous. In some settings, home phototherapy devices are available for moderate cases under medical supervision, which avoids hospitalisation.

Does sunlight work instead of phototherapy?

The idea of treating jaundice with sunlight is based on a real mechanism: sunlight does contain the blue wavelengths that can convert bilirubin. Indirect natural light, such as sitting near a window in a well-lit room, causes no harm to a mildly jaundiced baby who is already being medically monitored. But sunlight is not a safe substitute for medical phototherapy.

Direct sun exposure risks burning a newborn's thin, vulnerable skin even in a matter of minutes. Glass windows filter out much of the useful blue wavelength. The dose cannot be controlled or measured. And a baby who needs phototherapy needs bilirubin to fall quickly and reliably, which sunlight cannot achieve. Families in the region sometimes delay bringing a jaundiced baby to hospital because they believe daily sun exposure at home is sufficient. This delay is the situation in which kernicterus becomes possible.

If your baby has mild jaundice and is being monitored by a doctor who has told you no treatment is needed, gentle exposure to indirect natural light in a warm room causes no harm. The moment a doctor recommends phototherapy, that means the bilirubin level has reached a threshold where sunlight is not an adequate alternative.

Breast milk jaundice and breastfeeding jaundice: two different things

Breastfeeding is associated with two distinct types of jaundice that are often confused. The first is breastfeeding jaundice, which occurs in the first week when the baby is not getting enough milk. Frequent large stools are how newborns excrete bilirubin, and when feeding is insufficient, less stool means less bilirubin removed. The solution is improving feeding frequency and latch, not stopping breastfeeding.

The second is breast milk jaundice, which appears after the first week and can persist for several weeks. It occurs because some mothers' milk contains substances that slow the liver's processing of bilirubin. This condition is usually harmless and rarely requires stopping breastfeeding. When bilirubin is very high in a baby with breast milk jaundice, a brief pause in breastfeeding of 24 to 48 hours may be recommended by a doctor to allow levels to fall, after which breastfeeding resumes. This decision belongs to the clinician assessing the actual bilirubin level, not to a parent guessing at home.

In both cases, the default answer is not to stop breastfeeding. Continuing breastfeeding tends to help jaundice resolve faster than it hinders it. The AAP and WHO both recommend continuing breastfeeding through jaundice monitoring in the absence of a clear medical reason to pause.

What to watch for after leaving hospital

Many newborns are discharged from hospital within 24 to 48 hours of birth, which is exactly when bilirubin is still rising. An updated 2024 guideline published in JAAPA recommends follow-up with a healthcare provider within 24 to 48 hours of discharge to check bilirubin levels. If hospital-based measurement is not possible, a transcutaneous bilirubinometer, a handheld device touched to the skin, is an acceptable alternative in community settings.

At home, check your baby's skin colour daily in natural light, not under yellow indoor lighting which conceals yellow skin. Look at the face first, then the chest, then the belly, then the arms and legs. If yellowing is spreading downward or appears deeper than the day before, contact your doctor the same day.

A baby who feeds eight to twelve times every 24 hours, produces at least six wet nappies and regular yellow stools daily, and appears active and alert is processing bilirubin normally in most cases. Dehydration and insufficient feeding are the most common factors that extend jaundice and drive levels higher. Feeding frequently is both the best prevention and the most important part of home management.

You can use the Sihtak app to track your newborn's jaundice day by day in the first two weeks, log feeding frequency, and note any changes in skin colour or alertness to share with your doctor at the follow-up visit.

Frequently asked questions

When should I take my newborn to hospital for jaundice?

Go to the emergency department the same day if jaundice appears within the first 24 hours, if yellowing reaches the legs and feet, if the baby is very difficult to wake or refuses all feeds, if the cry sounds high-pitched and unusual, or if the baby arches their back. Mild yellowing confined to the face in an active, feeding baby in the first week is usually physiological and can be monitored.

Can sunlight treat my baby's jaundice?

Indirect natural light in a warm room does no harm to a mildly jaundiced baby under medical supervision. But it is not a safe substitute for phototherapy when bilirubin is at a level requiring treatment. Direct sunlight risks burning newborn skin. Once a doctor recommends phototherapy, that threshold has been crossed and light at home is not sufficient.

What is G6PD deficiency and why does it matter for jaundice?

G6PD is an enzyme that protects red blood cells. When it is deficient, red cells break down rapidly under certain stresses, releasing a surge of bilirubin very quickly. This is especially common across the Arab world. If your family has a history of G6PD deficiency, tell the maternity team at birth so the baby can be monitored closely from the start.

Can jaundice damage my baby's brain?

Yes, if bilirubin reaches very high levels without treatment it can deposit in the brain and cause permanent damage called kernicterus. This leads to cerebral palsy, hearing loss and intellectual disability. Kernicterus is entirely preventable with timely monitoring and phototherapy when needed. This is why early follow-up after leaving hospital matters.

Should I stop breastfeeding if my baby has jaundice?

In most cases, no. Breastfeeding frequently actually helps clear bilirubin by producing stools. Stopping breastfeeding can make jaundice last longer. The exception is when a doctor has measured bilirubin and decided a brief pause is needed for a specific reason. That is a clinical decision based on actual levels, not something to do based on appearance alone.

How long does normal newborn jaundice last?

Physiological jaundice in a full-term newborn typically lasts 7 to 14 days. In premature babies it may last up to three weeks. Jaundice persisting beyond this needs investigation. Breast milk jaundice can last several weeks but is usually harmless at the levels it reaches.

Is phototherapy painful or harmful?

Phototherapy is not painful. The baby lies under blue lights with protective eye covers, and feeding continues during breaks. Common temporary effects are mild skin redness, greenish stools and slight dehydration, which are managed by ensuring good fluid intake. The treatment has an established safety record and is used routinely for newborns worldwide.

Are premature babies at higher risk from jaundice?

Yes. Premature babies have less mature livers and process bilirubin more slowly. They are also often harder to feed adequately in the first days, which reduces bilirubin excretion through stool. Because of this, doctors use lower bilirubin thresholds to start phototherapy in premature infants compared to full-term newborns.

Sources

This content is for health education only and is not a substitute for medical advice. If you have symptoms that worry you, see your doctor.