Complications can develop from measles, some of which can be extremely serious.

It's estimated that around one in every 5,000 people with measles will die as a result of a serious complication.

Complications of measles are more likely to develop in certain groups of people, including:

• babies younger than one year old
• children with a poor diet
• children with a weakened immune system, such as those with AIDS or those having chemotherapy for leukaemia
• teenagers and adults

Children who are older than one year and otherwise healthy have the lowest risk of developing serious complications.

Common complications

More common complications of measles include:

• diarrhoea 
• vomiting
• middle ear infection (otitis media), which can cause earache
• eye infection (conjunctivitis)
• inflammation of the voice box (laryngitis)
• pneumonia, bronchitis and croup (infections of the airways and lungs)
• fits caused by a fever (febrile seizures)

Uncommon complications

Less common complications of measles include:

• liver infection (hepatitis)
• misalignment of the eyes (squint), if the virus affects the nerves and muscles of the eye
• infection of the membranes surrounding the brain and spinal cord (meningitis) and infection of the brain itself (encephalitis)

Rare complications

In rare cases, measles can lead to the following conditions:

• serious eye disorders, such as an infection of the optic nerve (the nerve that transmits information from the eye to the brain), known as optic neuritis, which can lead to blindness
• heart and nervous system problems
• a fatal brain complication known as subacute sclerosing panencephalitis (SSPE), which can sometimes occur several years after measles – however, this is very rare, occurring in only one in every 25,000 cases of measles

Pregnancy complications

If you are not immune to measles and you become infected while you are pregnant, there is a risk of:

• a miscarriage
• stillbirth
• your baby being born prematurely (before the 37th week of pregnancy)
• your baby having a low birthweight

If you're pregnant and you think you've come into contact with someone with measles and you know you're not immune, you should see your GP as soon as possible. Your GP can advise you about treatment to reduce your risk of developing measles. Read more about preventing measles.