undiagnosed

adjective

un·​di·​ag·​nosed ˌən-ˌdī-ig-ˈnōst 

-əg-, 

-zd

: not diagnosed : not identified through diagnosis

an undiagnosed illness

… the symptoms of the syndrome may be subtle and thus may remain undiagnosed.

—Dwight R. Robinson

a condition that often goes undiagnosed

Examples of undiagnosed in a Sentence

Recent Examples on the Web

Elizabeth’s mother Kerrie Struhs was imprisoned in 2019 for child neglect after Elizabeth's undiagnosed diabetes left her close to death. — ABC News, 22 Oct. 2026

Tuesday, the sheriff announced an autopsy found that Greer actually died from an undiagnosed medical condition. — J.d. Miles, CBS News, 20 Oct. 2026

New research suggests concussions can quietly shut down the brain’s control over testosterone, and the hormonal fallout often goes undiagnosed long after the headaches fade. — Samantha Agate, Miami Herald, 19 Oct. 2026

There’s a little resonance between Grace’s undiagnosed PTSD plot and a similar arc for Josh Lyman on The West Wing. — Sophie Brookover, Vulture, 15 Oct. 2026

Word History

First Known Use

1864, in the meaning defined above

Medical Definition

undiagnosed

adjective

un·​di·​ag·​nosed -ˈnōst 

: not diagnosed : eluding diagnosis

undiagnosed disease