diagnose

American  

[dahy-uhg-nohs, -nohz, dahy-uhg-nohs, -nohz] / ˈdaɪ əgˌnoʊs, -ˌnoʊz, ˌdaɪ əgˈnoʊs, -ˈnoʊz /

verb (used with object)

• diagnoses,
  present (3rd person singular)
• diagnosed,
  past participle,  past
• diagnosing
  present participle

1. to determine the identity of (a disease, illness, etc.) by a medical examination.

   The doctor diagnosed the illness as influenza.

2. 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.

3. to classify or determine on the basis of scientific examination.

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verb (used without object)

• diagnoses,
  present (3rd person singular)
• diagnosed,
  past participle,  past
• diagnosing
  present participle

1. to make a diagnosis.

diagnose British  

/ ˈdaɪəɡˌnəʊz /

verb

1. to determine or distinguish by diagnosis

2. (tr) to examine (a person or thing), as for a disease

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Other Word Forms

Derived Forms

• underdiagnose
  verb (used with object)
• diagnosable
  adjective
• undiagnosable
  adjective
• undiagnosed
  adjective
• well-diagnosed
  adjective

Inflected Forms

Participles

• diagnosing
  present
• diagnosed
  past

Conjugated Forms

Present

• diagnose
  simple
• diagnoses
  simple
• have diagnosed
  perfect
• has diagnosed
  perfect
• am diagnosing
  progressive
• are diagnosing
  progressive
• is diagnosing
  progressive
• have been diagnosing
  perfect progressive
• has been diagnosing
  perfect progressive

Past

• diagnosed
  simple
• had diagnosed
  perfect
• was diagnosing
  progressive
• were diagnosing
  progressive
• had been diagnosing
  perfect progressive

Future

• will diagnose
  simple
• will have diagnosed
  perfect
• will be diagnosing
  progressive
• will have been diagnosing
  perfect progressive

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.

Example Sentences

See Examples For:

diagnose diagnoses diagnosed diagnosing

And it left me with a question: Why is our mental-health system so quick to diagnose and so slow to examine the full context of a person’s suffering?

From MarketWatch ● Sep. 30, 2026

And he’ll undergo imaging to diagnose the injury.

From Los Angeles Times ● Sep. 27, 2026

Even if I were a doctor, I wouldn’t be able to diagnose him via random clips on the internet.

From Salon ● Sep. 17, 2026

She couldn’t understand why we could diagnose her osteoarthritis early yet couldn’t slow it down.

From The Wall Street Journal ● Sep. 13, 2026

The few doctors left in Kabul didn’t have the right equipment to diagnose what was ailing her or the right medication to make her better.

From "Shooting Kabul" by N. H. Senzai

South Korean activists campaigning for workplace safety in the nation's booming semiconductor industry called on the government on Wednesday to recognise the cancer diagnoses of three former SK hynix employees as work-related illnesses.

From Barron's ● Oct. 7, 2026

The proposed solutions are as divergent as the diagnoses.

From The Wall Street Journal ● Sep. 29, 2026

Helen said awareness of young onset dementia had grown since the 90s - but diagnoses still took too long.

From BBC ● Sep. 27, 2026

It adds that the NHS disclosure of this approach precedes a major government-commissioned review of the "colossal increases" in diagnoses of ADHD, autism and mental illness.

From BBC ● Sep. 25, 2026

At the time Theresa had not dared to; and though later she’d learned to talk professionally — to present cases — past differential diagnoses and treatment plans, she managed nothing.

From "Typical American" by Gish Jen

Magaña was diagnosed with bipolar and schizoaffective disorders as a young teen, but growing up in a large, traditional Mexican family, mental health wasn’t talked about as openly as it is today, she said.

From Los Angeles Times ● Oct. 10, 2026

But cortisol levels aren’t really the problem here—or the way that any of those issues are diagnosed.

From Slate ● Oct. 9, 2026

Shaun of the Dead and Mission: Impossible films star Simon Pegg has revealed he has been diagnosed with ADHD, which he said "confirmed a lot of stuff that I'd been wrestling with".

From BBC ● Oct. 8, 2026

Yoon began working at SK hynix's Icheon chip plant in 1996 and was diagnosed with cancer in 2018.

From Barron's ● Oct. 7, 2026

When the vet diagnosed her as deaf, he also found out she had some condition where she didn’t have a fully developed sense of touch.

From "Born a Crime: Stories from a South African Childhood" by Trevor Noah

Like many of the hundreds of others who have pitched their tents here to protest at Spain's housing crisis, she has no doubts when it comes to diagnosing the cause.

From BBC ● Oct. 8, 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

He had been diagnosing and treating the illness since he’d first set foot in Haiti.

From "Mountains Beyond Mountains" by Tracy Kidder and Michael French

Related Words

• analyze
• determine
• investigate
• pinpoint
• pronounce
• recognize