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

Lily's been fighting an undiagnosed bone marrow condition, but her mom says the music brought light to a tough journey. —Bryan West, Nashville Tennessean, 23 Oct. 2025

Lichtman previously said Mascia was suffering from an undiagnosed mental health problem at the time of the shooting and that the former trooper has been undergoing treatment. —Landon Mion, FOXNews.com, 23 Oct. 2025

The 83-year-old man’s family believes Theo is suffering from the beginning stages of undiagnosed dementia, according to WTVR. —Sam Gillette, PEOPLE, 17 Oct. 2025

Halsey continued by saying a lot of people who are bipolar remain undiagnosed because of these misunderstandings. —Mackenzie Cummings-Grady, Billboard, 16 Oct. 2025

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