Meningitis is an infection of the meninges, protective membranes that surround the brain and spinal cord. Infection can cause the meninges to become inflamed and swell, which can damage the nerves and brain.
This can cause symptoms such as a severe headache, vomiting, high fever, stiff neck and sensitivity to light. Many people (but not all) also develop a distinctive skin rash.
Symptoms can differ in young children and babies. See the "symptoms" section for more information.
Meningitis can be caused by:
- bacteria, such as streptococcus pneumoniae, the bacteria also responsible for pneumonia, which usually live harmlessly in your mouth and throat, and
- viruses, such as the herpes simplex virus.
Viral meningitis
Viral meningitis is the most common and less serious type of meningitis.
Viral meningitis is most common in young children and babies, especially in babies less than one year old.
Viral meningitis usually gets better by itself within a couple of weeks, without the need for specific treatment.
Bacterial meningitis
Bacterial meningitis is extremely serious and should be treated as a medical emergency.
If the bacterial infection is left untreated, it can cause severe damage to the brain and infect the blood (septicaemia), leading to death.
Treatment requires a transfer to an intensive care unit so the body's functions can be supported while antibiotics are used to fight the infection.
The number of cases has dropped sharply in recent years due to a successful vaccination programme that protects against many of the bacteria that can cause meningitis.
The treatment for bacterial meningitis has improved greatly. Several decades ago, almost all people with bacterial meningitis would die, even if they received prompt treatment. Now deaths occur in one in 10 cases, usually as a result of a delay in treatment.
Bacterial meningitis is most common in children and babies under the age of three, and in teenagers and young people aged 15-24.
The best way to prevent meningitis is to ensure that your family's vaccinations are up to date.