Due to the location of the mastoid bone inside the ear, mastoiditis can be difficult to treat. Treatment that isn't effective or that isn't administered before the mastoid is damaged can lead to serious health issues. These include:vertigo, or dizzinessfacial paralysishearing lossMeningitis: a bacterial infection of the membranes surrounding the brain and spinal cordA collection of pus on the outside of your brain and spinal cord (an epidural abscess)An infection that spreads throughout the body (sepsis)