Jaundice is caused by too much bilirubin in the blood. This is known as hyperbilirubinaemia.

Bilirubin is a yellow substance produced when red blood cells, which carry oxygen around the body, are broken down.

The bilirubin travels in the bloodstream to the liver. The liver changes the form of the bilirubin so that it can be passed out of the body in stools (faeces).

However, if there is too much bilirubin in the blood, or if the liver cannot get rid of it, excess bilirubin will cause jaundice.

Jaundice in babies

Jaundice is common in newborn babies because babies have a high level of red blood cells in their blood and these are broken down and replaced frequently. The liver in newborn babies is also not yet fully developed, so it is less effective at processing the bilirubin and removing it from the blood.

This means that the level of bilirubin in babies can be about twice as high as in adults.

By the time a baby is about two weeks old, they are producing less bilirubin and their liver is more effective at removing it from the body, which means the jaundice often corrects itself by this point without causing harm.

Breastfeeding

Breastfeeding your baby can increase their chances of developing jaundice, but there is no need to stop breastfeeding your baby if they have jaundice as the symptoms will normally pass in a few weeks and the benefits of breastfeeding outweigh any potential risks associated with the condition.

If your baby needs to be treated for jaundice, he or she may require extra fluids and more frequent feeds during treatment. See treating newborn jaundice for more information.

The reason why breastfed babies are more likely to develop jaundice is unclear, although a number of theories have been suggested. For example, it may be that breast milk contains certain substances that reduce the ability of the liver to process bilirubin.

Newborn jaundice thought to be linked to breastfeeding is sometimes called “breast milk jaundice”.

Underlying health conditions

In some cases, jaundice may be the result of another health problem. This is sometimes called “pathological jaundice”.

Some causes of pathological jaundice include:

• an underactive thyroid gland (hypothyroidism) – where the thyroid gland does not produce enough hormones
• blood group incompatibility – when the mother and baby have different blood types, and these are mixed during the pregnancy or the birth
• rhesus factor disease – a condition that can occur if the mother has rhesus-negative blood and the baby has rhesus-positive blood
• an inherited enzyme deficiency (enzymes are proteins that speed up and control chemical reactions in the body) – such as a deficiency of glucose-6-phosphate-dehydrogenase (G-6-PD), an enzyme that helps red blood cells function
• a urinary tract infection 
• Crigler-Najjar syndrome – an inherited condition that adversely affects the enzyme responsible for processing bilirubin, leading to a build-up of bilirubin
• an obstruction or defect in the biliary system – the biliary system is made up of the bile ducts and gall bladder, and it creates and transports bile (a fluid used to help digest fatty foods)

Blood

Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.

Intestines

The intestines are the part of the digestive system between the stomach and the anus that digests and absorbs food and liquid.

Liver

The liver is the largest organ in the body. Its main jobs are to secrete bile (to help digestion), detoxify the blood and change food into energy.

Oxygen

Oxygen is an odourless, colourless gas that makes up about 20% of the air we breathe.

Kernicterus is a rare but serious complication of untreated jaundice in babies caused by excess bilirubin damaging the brain or central nervous system.

In newborn babies with very high levels of bilirubin in the blood (hyperbilirubinaemia), the bilirubin can cross the thin layer of tissue that separates the brain and the blood (the blood-brain barrier). The bilirubin can damage the brain and spinal cord, which can be life-threatening.

Brain damage caused by high levels of bilirubin is also called bilirubin encephalopathy.

Your baby may be at risk of developing kernicterus if:

• they have a very high level of bilirubin in their blood
• the level of bilirubin in their blood is rising rapidly
• they do not receive any treatment

Kernicterus is now extremely rare in the UK, affecting less than 1 in every 100,000 babies.

Initial symptoms of kernicterus in babies include:

• decreased awareness of the world around them – for example they may not make any reaction when you clap your hands in front of their face
• their muscles become unusually floppy like a rag doll (hypotonia)
• poor feeding

As kernicterus progresses, additional symptoms can include seizures (fits) and arching of the neck and/or spine.

Treatment for kernicterus involves using an exchange transfusion as used in the treatment of newborn jaundice.

If significant brain damage occurs before treatment, a child can develop serious and permanent problems, such as:

• cerebral palsy – a condition that that affect a child’s movement and co-ordination
• hearing loss, which can range from mild to severe
• learning difficulties
• involuntary twitching of different parts of their body
• problems maintaining normal eye movements – people affected by kernicterus have a tendency to gaze upwards or from side to side rather than straight ahead
• the normal development of the teeth can be disrupted resulting in teeth that are misshapen, discoloured and vulnerable to tooth decay 

Blood

Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.

Brain

The brain controls thought, memory and emotion. It sends messages to the body controlling movement, speech and senses.

Your baby will be checked for jaundice within 72 hours of being born, but you should keep an eye out for signs of the condition after you return home because it can sometimes take up to a week to appear.

When you are at home with your baby, you should look out for yellowing of their skin or the whites of their eyes. Gently pressing your fingers on the tip of their nose or on their forehead can make it easier for you to spot any yellowing.

You should also check your baby’s urine and stools (faeces). Your baby may have jaundice if their urine is yellow (a newborn baby’s urine should be colourless) or their stools are pale.

You should speak to your midwife, health visitor or GP as soon as possible if you think your baby may have jaundice. Tests will need to be carried out to determine whether any treatment will be necessary.

Read more about the symptoms of jaundice in babies.

Visual examination

A visual examination of your baby will be carried out to look for signs of jaundice. Your baby will need to be undressed during this so their skin can be looked at under good, preferably natural, light.

Other things that may also be checked include:

• the whites of your baby’s eyes
• your baby’s gums
• the colour of your baby’s stools or urine

Bilirubin test

If it’s thought that your baby may have jaundice, the level of bilirubin (the yellow substance produced when red blood cells are broken down) in your baby’s blood will need to be tested. This can be done using:

• a small device called a bilirubinometer, which beams light onto your baby’s skin. By analysing how the beams of light are reflected off the skin, or absorbed by the skin, the device calculates the level of bilirubin in the blood.
• a blood test of a sample of blood usually obtained by pricking your baby’s heel with a needle. The level of bilirubin in the liquid part of the blood (the serum) is then measured.

In most cases, a bilirubinometer is used to check for jaundice in babies. Blood tests are usually only necessary if your baby developed jaundice within 24 hours of birth or the bilirubinometer reading is particularly high.

The level of bilirubin detected in your baby’s blood is used to decide whether any treatment is necessary.

Read more about treating jaundice in babies

Further tests

Some further tests may need to be carried out if your baby’s jaundice lasts longer than two weeks, or if treatment is required. The tests will help to determine whether there is another underlying cause for the raised levels of bilirubin.

Possible tests include:

• finding out the baby’s blood group by testing a sample of their blood to see if their blood group is incompatible with their mother’s
• a Coombs test, which involves testing a sample of blood to detect antibodies (infection-fighting proteins) that may be attached to the surface of your baby’s red blood cells
• finding out the packed cell volume of your baby’s blood – this tests the number of cells in the blood
• testing a sample of your baby’s blood, urine or cerebrospinal fluid (the fluid that surrounds the brain and spinal cord) for infections
• testing for the enzyme glucose-6-phosphate dehydrogenase (G-6-PD) in a sample of your baby’s blood to see whether they have a G-6-PD deficiency
• carrying out a full blood count on a sample of your baby’s blood – this involves several tests to check different parts of the blood for a number of other possible problems

Antibodies

Antibodies are your body’s natural defence against any foreign antigens that enter your blood. An antibody is a protein produced by the body to neutralise or destroy disease-carrying organisms and toxins.

Blood

Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.

Enzymes

Enzymes are proteins that speed-up and control chemical reactions, such as digestion, in the body.

Liver

The liver is the largest organ in the body. Its main jobs are to secrete bile (to help digestion), detoxify the blood and change food into energy.

Jaundice is a common and usually harmless condition in newborn babies that causes yellowing of the skin and the whites of the eyes. The medical term for jaundice in babies is neonatal jaundice.

Other symptoms of newborn jaundice can include:

• yellowing of the palms of the hands or soles of the feet
• dark, yellow urine (a newborn baby’s urine should be colourless)
• pale coloured stools (faeces) instead of yellow- or orange-coloured stools

The symptoms of newborn jaundice usually develop two to three days after the birth and tend to get better without treatment by the time the baby is about two weeks old.

Read more about the symptoms of jaundice in babies.

When to seek medical advice

Your baby will usually be examined for signs of jaundice within 72 hours of being born.

If your baby develops signs of jaundice after this time, speak to your midwife, health visitor or GP as soon as possible for advice.

While jaundice is not usually a cause for concern, it’s important to determine whether your baby requires treatment.

Read more about diagnosing jaundice in babies.

Why does my baby have jaundice?

Jaundice is caused by the build-up of bilirubin in the blood. Bilirubin is a yellow substance produced when red blood cells are broken down.

Jaundice is common in newborn babies because babies have a high level of red blood cells in their blood and these are broken down and replaced frequently. The liver in newborn babies is also not fully developed, so it is less effective at removing the bilirubin from the blood.

By the time a baby is about two weeks old, their liver is more effective at processing bilirubin, so jaundice often corrects itself by this age without causing any harm.

In a small number of cases, jaundice can be the sign of an underlying health condition. This is often the case if jaundice develops shortly after birth (within the first 24 hours).

Read more about the causes of jaundice in babies.

Who is affected

Jaundice is one of the most common conditions that can affect newborn babies. It is estimated that 6 out of every 10 babies will develop jaundice, including 8 out of 10 babies born prematurely (babies born before the 37th week of pregnancy).

However, only around 1 in 20 babies has a high enough level of bilirubin in their blood to need treatment.

For reasons that are unclear, breastfeeding a baby increases the risk of them developing jaundice, which can often persist for a month or longer. However, in most cases the benefits of breastfeeding far outweigh any risks associated with jaundice.

Treating newborn jaundice

Most cases of jaundice in babies do not require treatment as the symptoms normally pass within 10-14 days (although in a minority of cases symptoms can last longer).

Treatment is usually only recommended if tests show a baby has very high levels of bilirubin in their blood because there is a small risk in these cases that the bilirubin could pass into the brain and cause brain damage (see below).

There are two main treatments that can be carried out in hospital to quickly reduce your baby’s bilirubin levels. These are:

• phototherapy – a special type of light shines on the skin, which alters the bilirubin into a form that can be more easily broken down by the liver
• an exchange transfusion – a type of blood transfusion where small amounts of your baby’s blood are removed and replaced with blood from a matching donor

Most babies respond well to treatment and can leave hospital after a few days.

Read more about treating jaundice in babies.

Complications

If a baby with very high levels of bilirubin is not treated, there is a risk they could develop permanent brain damage. This is known as kernicterus.

Fortunately, kernicterus is very rare in the UK, affecting less than 1 in every 100,000 babies born. There were only three reported cases of kernicterus in England during 2012-13.

Read more about the complications of jaundice in babies.

The Map of Medicine is used by doctors throughout the NHS to determine the best treatment options for their patients. NHS Choices offers everyone in England exclusive and free access to this cutting-edge internet resource, which lets you see exactly what your doctor sees.

The information in the Map has been approved by the UK’s leading clinical experts, is based on the best available clinical evidence, and is continually updated. To take advantage of this unique resource go to:

Map of Medicine: neonatal jaundice

Jaundice usually appears about three days after birth and disappears by the time the baby is two weeks old.

In premature babies, who are more prone to jaundice, it can take five to seven days to appear and usually lasts about three weeks. It also tends to last longer in babies who are breastfed, affecting some babies for a few months. 

If your baby has jaundice, their skin will look slightly yellow. The yellowing of the skin usually starts on the head and face, before spreading to the chest and stomach. In some babies, the yellowing reaches their legs and arms.

Yellowing may appear more pronounced if you press an area of skin down with your finger.

Changes in skin colour can be more difficult to spot if your baby has a darker skin tone. In these cases, yellowing may be more obvious elsewhere, such as:

• in the whites of their eyes
• inside their mouth
• on the soles of their feet
• on the palms of their hand

Other associated symptoms of newborn jaundice can include:

• poor sucking or feeding
• sleepiness
• a high-pitched cry
• limpness (floppiness)
• dark, yellow urine (a newborn baby’s urine should be colourless)
• pale stools (faeces) instead of yellow or orange stools

When to seek medical advice

Your baby will usually be examined for signs of jaundice within 72 hours of being born.

If your baby develops signs of jaundice after this time, speak to your midwife, health visitor or GP as soon as possible for advice.

While jaundice is not usually a cause for concern, it’s important to determine whether your baby requires treatment.

Read more about diagnosing jaundice in babies.

You should speak to your midwife, health visitor or GP if your baby develops jaundice. They will be able to assess whether treatment is needed.

Treatment is usually only necessary if your baby has high levels of a substance called bilirubin in their blood, so tests will need to be carried out to check this. See diagnosing jaundice in babies for more information about the tests used.

Most babies with jaundice do not need treatment because the level of bilirubin in their blood is found to be low. In these cases, the condition will usually get better within 10-14 days and won’t cause any harm to your baby.

If treatment is felt to be unnecessary, you should continue to breastfeed or bottle feed your baby regularly, waking them up for feeds if necessary. If your baby’s condition gets worse or does not disappear after two weeks, contact your midwife, health visitor or GP.

Prolonged newborn jaundice (lasting longer than two weeks) can occur if your baby was born prematurely or if he or she is solely breastfed, and it will usually improve without treatment. However, further tests may be recommended if the condition lasts this long, to check for any underlying health problems.

If your baby’s jaundice does not improve over time, or tests show they have high levels of bilirubin in their blood, they may be admitted to hospital and treated with phototherapy or an exchange transfusion.

These treatments are recommended to reduce the risk of a rare but serious complication of jaundice called kernicterus, which can cause brain damage. See complications of jaundice in babies for more information about this.

Phototherapy

Phototherapy is treatment with light. It is used in some cases of newborn jaundice to lower the bilirubin levels in your baby’s blood through a process called photo-oxidation. Oxidation is the process of adding oxygen to change a substance (in this case, the bilirubin).

The photo-oxidation converts the bilirubin into a substance that dissolves easily in water. This makes it easier for your baby’s liver to break down and remove the bilirubin from their blood.

There are two main types of phototherapy.

• Conventional phototherapy – where your baby is laid down under a halogen or fluorescent lamp with their eyes covered to prevent damage to eyes.
• Fibre optic phototherapy – where your baby lies on a blanket that incorporates fibre optic cables. Light travels through the fibreoptic cables and shines onto your baby’s back.

In both methods of phototherapy, the aim is to expose your baby’s skin to as much light as possible.

Conventional phototherapy is the treatment tried first in most cases, although fibre optic phototherapy may be used first if your baby was born prematurely. These types of phototherapy will usually be stopped for 30 minutes every three to four hours so that you can feed your baby, change their nappy and give them a hug.

If your baby’s jaundice does not improve after conventional or fibre optic phototherapy, continuous multiple phototherapy may be offered. This involves using more than one light and often a fibre optic blanket at the same time.

Treatment will not be stopped during continuous multiple phototherapy. Instead, milk that has been squeezed out of your breasts in advance may be provided through a tube into your baby’s stomach, or fluids may be provided into one of their veins (intravenously).

During phototherapy, you baby’s temperature will be monitored to ensure they are not getting too hot and they will be checked for signs of dehydration. Your baby may need to have intravenous fluids if they are becoming dehydrated and are not able to drink a sufficient amount.

The bilirubin levels will be tested every four to six hours after phototherapy has started. Once levels start to fall, they will be checked every 6 to 12 hours.

Phototherapy will be stopped when the bilirubin level falls to a safe level, which usually takes a day or two.

Phototherapy is generally very effective for newborn jaundice and it has very few side effects, although your baby may develop a temporary rash or tan as a result of the treatment.

Exchange transfusion

A blood transfusion, known as an exchange transfusion, may be recommended if your baby has particularly high levels of bilirubin in their blood or if phototherapy has not been effective.

During an exchange transfusion, small amounts of your baby’s blood are removed through a thin plastic tube placed into blood vessels in their umbilical cord, arms or legs. The blood is then replaced with blood from a suitable matching donor (someone with the same blood group).

As the new blood will not contain bilirubin, the overall level of bilirubin in your baby’s blood will quickly fall.

Your baby will be monitored throughout the transfusion process, which can take several hours to complete. Any problems that may arise, such as bleeding, will be treated.

Your baby’s blood will be tested within two hours of treatment to check if it has been successful. If the level of bilirubin in your baby’s blood remains high, the procedure may need to be repeated.

Other treatments

If jaundice is caused by an underlying health problem, such as an infection, this will usually need to be treated.

If the jaundice is caused by rhesus disease (when the mother has rhesus-negative blood and the baby has rhesus-positive blood), intravenous immunoglobulin (IVIG) may be used.

The immunoglobulin is a solution of antibodies (proteins produced by the body to destroy disease-carrying organisms) from healthy donors. It is injected into a vein (intravenous).

IVIG will usually only be used if phototherapy alone has not worked, and the level of bilirubin in the blood is continuing to rise.

Antibodies

Antibodies are your body’s natural defence against any foreign antigens that enter your blood. An antibody is a protein that is produced by the body to neutralise or destroy disease-carrying organisms and toxins.

Blood

Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.

Liver

The liver is the largest organ in the body. Its main jobs are to secrete bile (to help digestion), detoxify the blood and change food into energy.

Oxygen

Oxygen is an odourless, colourless gas that makes up about 20% of the air we breathe.

Retina

The retina is the nerve tissue lining the back of the eye, which senses light and colour, and sends it to the brain as electrical impulses.