​Meningitis is often due to the presence of micro-organisms, which and be simply divided into those due to bacteria (septic meningitis) and those due to viruses (aseptic meningitis).

Meningitis means that the covering lining over the brain and spinal cord is inflamed. The bacterial meningitis are less common but generally more serious, whereas the viral meningitis are more common but much less serious in its clinical course.

For viral meningitis, most children recover completely form the acute illness.  However non-specific symptoms such as malaise, tiredness, dizziness and headaches may continue weeks to months after the acute illness.  Rarely there can be hearing impairment.  Some have reported behavioural or learning problems years after recovery.

Bacterial meningitis is much more serious, and death can occur due to septicemic (blood poisoning) shock from the bacterial organism.  Death can also occur due to severe brain swelling that results in compression/pressure on the vital centres in the brainstem.  Mortality from bacterial meningitis is approximately 5% - 20% depending on the virulence of micro-organism involved.  Other common complications in the acute illness include fluid and electrolyte abnormalities and even seizures. 

​Following prompt treatment with appropriate intravenous antibiotics, children that survive Bacterial meningitis may also develop complications such as hydrocephalus (obstruction or impaired re-absorption of the fluid system in the brain due to scarring), which may then require an operation for relieve of the obstruction.  Up to 30% of bacterial meningitis is complicated by clinical deafness.

With two of the common bacterial organisms, this complication rate of deafness can be reduced with concomitant administration of steroid with the antibiotics at the initiation of the treatment.  Potential long term sequelae will include physical and/or mental disability due to the inflammatory reaction, which can cause damage to the brain itself.  These neurological abnormalities persist without complete recovery in up to 20% of the survivors.