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

In a confessional, the reality TV star says having an undiagnosed chronic condition has taken a mental toll on her. — Anthony Robledo, USA Today, 4 Aug. 2026

Nearly one in five women live with obstructive sleep apnea, yet nine out of 10 remain undiagnosed. — Hanna Wickes, Kansas City Star, 4 Aug. 2026

Women with sleep apnea often don’t snore loudly, which is one reason so many go undiagnosed. — Hanna Wickes, Miami Herald, 4 Aug. 2026

Nearly one in five women have obstructive sleep apnea, yet nine out of 10 women with OSA remain undiagnosed, missing years of treatment for a disorder tied to heart disease, stroke and cognitive decline. — Hanna Wickes, Charlotte Observer, 3 Aug. 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