diagnose
Americanverb (used with object)
-
diagnoses,
present (3rd person singular)
-
diagnosed,
past participle, past
-
diagnosing
present participle
-
to determine the identity of (a disease, illness, etc.) by a medical examination.
The doctor diagnosed the illness as influenza.
-
to ascertain the cause or nature of (a disorder, malfunction, problem, etc.) from the symptoms.
The mechanic diagnosed the trouble that caused the engine knock.
-
to classify or determine on the basis of scientific examination.
verb (used without object)
-
diagnoses,
present (3rd person singular)
-
diagnosed,
past participle, past
-
diagnosing
present participle
verb
-
to determine or distinguish by diagnosis
-
(tr) to examine (a person or thing), as for a disease
Other Word Forms
Derived Forms
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underdiagnoseverb (used with object)
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diagnosableadjective
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undiagnosableadjective
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undiagnosedadjective
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well-diagnosedadjective
Inflected Forms
Participles
Conjugated Forms
Present
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diagnosesimple
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diagnosessimple
-
have diagnosedperfect
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has diagnosedperfect
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am diagnosingprogressive
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are diagnosingprogressive
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is diagnosingprogressive
-
have been diagnosingperfect progressive
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has been diagnosingperfect progressive
Past
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diagnosedsimple
-
had diagnosedperfect
-
was diagnosingprogressive
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were diagnosingprogressive
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had been diagnosingperfect progressive
Future
Etymology
Origin of diagnose
First recorded in 1860–65; back formation from diagnosis
Explanation
If you diagnose a disease, you recognize it by the signs and symptoms your patient shows. Your high temperature and the green crud you keep coughing up will allow your doctor to diagnose your bronchitis. The verb diagnose was first used in medicine, meaning "make a diagnosis," or identify a disease by observation of symptoms. Use it to describe the process of figuring it out. If you have bad gut pain, ask your doctor to diagnose your condition. You can also use diagnose for other problems, like if you diagnose poverty and malnutrition as the real causes of a student's terrible behavior, or diagnose the virus that caused your computer to crash.
Vocabulary lists containing diagnose
100 Great Words from "Fahrenheit 451" -- Part I Vocabulary
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Mother's Day Words: What Mothers Do
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“About Edward Jenner” from the Jenner Institute
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
When our system is designed solely to diagnose the presence or absence of disease, one organ at a time, people have no baseline against which to make broader lifestyle decisions.
From MarketWatch ● Oct. 5, 2026
After Paul's death, Kate wrote to the health board to complain about how long it took to diagnose him with scabies.
From BBC ● Sep. 30, 2026
And he’ll undergo imaging to diagnose the injury.
From Los Angeles Times ● Sep. 27, 2026
Even in some of the most severe cases, hormone levels sometimes dropped below the minimum thresholds typically used to diagnose primary aldosteronism.
From Science Daily ● Sep. 14, 2026
“Yeah, true. Not that either of us could diagnose her without seeing her, but I suspect she’ll be home soon.”
From "Paper Towns" by John Green
The study wasn’t focused on healthcare specifically, but it raises important questions about whether patients and doctors using different languages can reliably receive consistent information about diagnoses, treatment options, and medical risks.
From Slate ● Oct. 16, 2026
There are two main types of lung cancer: "small cell" cancers, which spread aggressively and make up about 10 to 15% of diagnoses, and "non-small cell" cancers, which make up the vast majority.
From Barron's ● Oct. 14, 2026
Prostate cancer diagnoses have quadrupled in people under 50 since 2001, while cases of bowel, kidney and uterine cancers have more than doubled, the paper reports.
From BBC ● Oct. 6, 2026
A series of articles in The Wall Street Journal reported that UnitedHealth received billions of dollars in federal payments by adding diagnoses to patients records, including some diagnoses that were questionable or inaccurate.
From The Wall Street Journal ● Oct. 5, 2026
Gruby diagnoses a heart problem: that’s what is causing his great exhaustion.
From "Vincent and Theo: The Van Gogh Brothers" by Deborah Heiligman
The former University of Virginia standout was reportedly diagnosed with the Grade 4 cancer last year and briefly went into remission, but the tumors returned in July, according to Houston news site Chron.
From Los Angeles Times ● Oct. 16, 2026
The man was in his fifties when he was diagnosed with mild cognitive impairment caused by Alzheimer's disease.
From Science Daily ● Oct. 15, 2026
The therapy, which was approved in May, works in patients with a specific genetic mutation called ESR1 who have failed hormone therapy, which represents around 1% of all newly diagnosed breast-cancer patients globally.
From The Wall Street Journal ● Oct. 15, 2026
The 40-year-old Kenyan man who died on 5 October was diagnosed with Ebola shortly after being admitted to hospital in the capital, Nairobi.
From BBC ● Oct. 14, 2026
It took four months before doctors diagnosed me with cystic fibrosis.
From "The Freedom Writers Diary" by The Freedom Writers
"I have been diagnosing PCD for 20 years by examining their cilia waveform, length, cell size and shape," he said.
From BBC ● Oct. 9, 2026
Healthcare professionals “are often undertrained and ill-equipped in diagnosing elder abuse.”
From MarketWatch ● Sep. 24, 2026
Modern therapies can help many patients achieve remission, but diagnosing and managing IBD remains challenging.
From Science Daily ● Sep. 20, 2026
I’m also a physician, trained in a profession that asks us to take action by identifying risk factors, diagnosing diseases, and intervening whenever possible.
From Slate ● Aug. 29, 2026
Minya pronounced, as though diagnosing a disease, “Happy.”
From "Strange the Dreamer" by Laini Taylor
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Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
