[2] Meningism involves the triad (3-symptom syndrome) of nuchal rigidity (neck stiffness), photophobia (intolerance of bright light) and headache.

It therefore requires differentiating from other CNS problems with similar symptoms, including meningitis and some types of intracranial hemorrhage.

Although nosologic coding systems, such as ICD-10 and MeSH, define meningism/meningismus as meningitis-like but in fact not meningitis, many physicians use the term meningism in a loose sense clinically to refer to any meningitis-like set of symptoms before the cause is definitively known.

[citation needed] Kernig's sign (after Waldemar Kernig (1840–1917), a Russian neurologist) is positive when the thigh is flexed at the hip and knee at 90 degree angles, and subsequent extension in the knee is painful (leading to resistance).

[citation needed] Jozef Brudzinski (1874–1917), a Polish pediatrician, is credited with several signs in meningitis.