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

Being undiagnosed for decades also cost us my fertility, depleting my ovarian reserve and leading to miscarriage after miscarriage with IVF and IUIs. —Kristina Kasparian, SELF, 22 Apr. 2026

His physician ran several tests that didn't reveal anything, so Sasse's doctor referred him to a gastroenterologist, believing the cause could be undiagnosed celiac or lactose intolerance. —Rachel Raposas, PEOPLE, 10 Apr. 2026

The series poignantly addresses the complexities of teenage struggles, particularly through Justin’s undiagnosed ADHD and Keisha’s experience of trauma, emphasizing the importance of unconditional support and the intersection of mental health with race and class in today’s world. —Hilary Lewis, HollywoodReporter, 9 Apr. 2026

Snoring can sometimes be a sign of an undiagnosed sleep disorder, such as OSA. —Lindsay Curtis, Verywell Health, 9 Apr. 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