Depends. The natural history of meningitis depends on the causal agent. For example, Meningococcal meningitis can progress rapidly with the patient becoming gravely ill over a period of 24 to 48 hours. Other types of meningitis may progress more slowly. Host factors also play a role. Persons with impaired immune function may be more susceptible, and become ill more quickly.
Stages of meningitis. The earliest signs of meningitis are fever stiff neck. Course progresses through elevation of temperature, altered state of alertness and responding, seizures, and symptoms that may appear like a stroke and abnormalities of cognitive ability. . Untreated or if treatment is not effective, course may lead to death.