The mastoid is a component of the middle ear, and mastoiditis of the middle ear is an acute purulent inflammation of the mucosal bone of the mastoid air chamber, which is part of otitis media. What is usually referred to as mastoiditis is a more serious purulent infection of the mastoid bone, mostly caused by strong bacterial virulence, weak patient resistance, and acute otitis media that is not controlled in a timely manner. Most middle ear mastoiditis is due to acute suppurative otitis media, which is not treated in a timely manner and is not completely healed, and therefore can become otitis media. The presence of rhinitis, sinusitis, and tonsillitis may also allow bacteria to repeatedly invade the middle ear cavity and incubate in the middle ear, causing middle ear mastoiditis. The symptoms of middle ear mastoiditis are often seen in children, and the seriousness of the condition can cause destruction of the mastoid bone to form an abscess behind the ear, or cause facial paralysis, dizziness and deafness, or even infection of the skull causing meningitis and brain abscess. The symptoms of middle ear mastoiditis are not treated with drugs alone, and patients are advised to seek treatment from a professional ENT hospital.