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

Going undiagnosed with sleep apnea doesn’t just mean dealing with more fatigue, irritability, and restless nights (though that’s reason enough, in our book, to seek out care). —Erica Sloan, SELF, 25 June 2025

Even in developed countries, many go undiagnosed due to gaps in insurance coverage and access to advanced imaging technology. —Sindhya Valloppillil, Forbes.com, 23 June 2025

One of Afrin’s first patients had spent a decade with undiagnosed fatigue, as well as sudden bouts of itching across her body. —Kate Raphael, Discover Magazine, 23 June 2025

Many people only visit their doctor once or twice a year, which may allow potential problems to go unnoticed and undiagnosed for months. —Bestreviews, Chicago Tribune, 10 June 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