Meningitis can be caused by various micro-organisms, classified as bacterial (septic meningitis) or viral (aseptic meningitis).

Meningitis is the inflammation of the membranes covering the brain and spinal cord. Viral meningitis is more common and generally less severe, while bacterial meningitis is less common but more severe.

In viral meningitis, most children recover completely, but some may experience lingering symptoms such as malaise, dizziness and headaches. Rare complications include hearing impairment or long-term behavioural or learning issues.

Bacterial meningitis is can be life-threatening, with potential complications including septic shock or severe brain swelling. Mortality rates vary from 5–20%, depending on the virulence of the bacteria. Acute complications can include fluid and electrolyte imbalances and seizures.

Prompt treatment with intravenous antibiotics is crucial for bacterial meningitis. Post-recovery complications may include hydrocephalus, requiring surgical intervention. Clinical deafness can occur up to 30% of cases, but the risk can be reduced by administering steroids alongside antibiotics at the onset of treatment. Long-term sequelae, including physical or mental disabilities, persist in up to 20% of survivors due to the brain damage caused by the inflammatory response.