Meningism is the triad of nuchal rigidity, photophobia (intolerance of bright light) and headache. It is a sign of irritation of the meninges, such as seen in meningitis, subarachnoid hemorrhage and various other diseases.

Nuchal rigidity is the inability to flex the head forward due to rigidity of the neck muscles. Brudzinski's sign is involuntary lifting of the legs in meningeal irritation when lifting a patient's head.