Blood cultures: Blood drawn is sent to a laboratory and placed in a special dish to see if it grows microorganisms, particularly bacteria

Imaging: X-rays and scans of the head, chest or sinuses may reveal swelling or inflammation. These tests can also help your doctor look for infection in other areas of the body that may associate with meningitis.

Spinal tap:  The CSF fluid often shows a low sugar (glucose) level along with an increased white blood cell count and increased protein.