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

Such a test could potentially help diagnose Alzheimer's disease, determine its stage, and identify a patient's particular disease subtype.

From Science Daily ● Jul. 22, 2026

Start-up Wunderfix meanwhile offers repair services linking retailers, customers and shops via an application that allows cyclists to diagnose and, where possible, repair their bicycles themselves.

From Barron's ● Jun. 28, 2026

That has attracted a parade of onlookers eager to see and, in some cases, diagnose the situation.

From The Wall Street Journal ● Jun. 18, 2026

The team says the findings could point to new ways to diagnose and treat Alzheimer's disease.

From Science Daily ● Jun. 12, 2026

It is possible to quickly diagnose the health of a marriage.

From "Blink" by Malcolm Gladwell

Even so, diagnoses among younger people have continued to increase.

From Science Daily ● Jul. 22, 2026

Risk increases with age and older adults still make up the largest proportion of new diagnoses.

From BBC ● Jul. 22, 2026

We found that expansion states saw more early-stage cancer diagnoses, meaning tumors were more likely to be caught while still treatable.

From Salon ● Jul. 19, 2026

There are just two medications approved by the Food and Drug Administration across all eating-disorder diagnoses: Prozac for bulimia and Vyvanse for binge-eating disorder.

From The Wall Street Journal ● Jul. 8, 2026

“Yeah, it’s like that at first. Mainly because diagnoses change, but also because the words themselves carry so much baggage. Know what I mean?”

From "Challenger Deep" by Neal Shusterman

Although none of the participants had a diagnosed mental health condition, the findings may offer clues about why psilocybin has shown therapeutic potential for depression, anxiety, and addiction.

From Science Daily ● Jul. 22, 2026

She announced the news about her dad, Martin Whiley, in an Instagram post on Tuesday, having previously revealed on her podcast that he had been diagnosed with Parkinson's disease.

From BBC ● Jul. 22, 2026

Because none of the 28 volunteers had a diagnosed mental health condition, the team was able to perform a broader range of tests than might have been possible in a clinical patient group.

From Science Daily ● Jul. 22, 2026

“Unfortunately, raptors get lead poisoning often, and that’s one of the problems we deal with,” she said, noting that their recent patient has yet to be diagnosed with this.

From Los Angeles Times ● Jul. 20, 2026

Then my syndrome was diagnosed by the doctors.

From "The London Eye Mystery" by Siobhan Dowd

These particles may offer new biomarkers for diagnosing Alzheimer's disease and determining how far it has progressed.

From Science Daily ● Jul. 22, 2026

The “why” could be bad luck, better awareness in diagnosing concussions or something else.

From Los Angeles Times ● Jun. 14, 2026

The AHA and three medical societies published the first guidelines for diagnosing and treating the disorder.

From The Wall Street Journal ● Jun. 12, 2026

I know that real problem-solving starts with diagnosing the root cause.

From BBC ● May 29, 2026

He asked Howard Jones to contribute an article recording his memories of diagnosing Henrietta’s tumor.

From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot

Related Words

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