Complications during illness with meningitis may include:
Prolonged fever. Fever caused by bacterial meningitis usually goes away after 3 to 6 days of treatment with antibiotics. Fever that continues after 6 days on antibiotics or that goes away and returns may mean that the antibiotic is not killing the bacteria. On rare occasions fever is caused by other conditions, including reactions to medicines used to treat meningitis.
Syndrome of inappropriate antidiuretic hormone (SIADH). This complication of bacterial meningitis may develop 1 to 2 days after antibiotics have been started. SIADH causes large amounts of fluid to build up in the body. If SIADH is not treated, coma and death can occur.