Other medical conditions may cause symptoms similar to those of meningitis, such as fever, headache, and vomiting. These conditions include:

• Influenza. This common viral infection produces symptoms of fever, headache, chills, muscle aches, and fatigue.
• Viral hepatitis. The liver becomes inflamed because of viral infection. Symptoms can include fever and headache.
• Mononucleosis. An illness caused by the Epstein-Barr virus, mononucleosis produces fever, sore throat, and enlargement of lymph nodes.
• Bacterial endocarditis. This infection of the heart valves can cause symptoms very similar to viral meningitis.
• Reaction to vaccination against the diseases of measles, mumps, chickenpox, smallpox, and rabies.