di·​ag·​nose | \ ˈdī-ig-ˌnōs How to pronounce diagnose (audio) , -ˌnōz, ˌdī-ig-ˈnōs How to pronounce diagnose (audio) , -ˈnōz, -əg- \
diagnosed; diagnosing

Definition of diagnose

transitive verb

1a : to recognize (something, such as a disease) by signs and symptoms The other method of diagnosing gallstones is through an ultrasound examination, which has the advantages of being simple, safe and quick.— G. Timothy Johnson Pulmonary embolus was diagnosed in two of the actively treated patients …— Richard D. Sautter et al.
b : to recognize a disease or condition in The physicist and cosmologist was diagnosed with Lou Gehrig's disease when he was a 21-year-old student at Cambridge University.— Maria Cheng
2 : to analyze the cause or nature of The mechanic diagnosed the problem with the engine.

intransitive verb

: to identify a disease from its signs and symptoms : to make a diagnosis

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Other Words from diagnose

diagnosable or diagnoseable \ ˌdī-​ig-​ˈnō-​sə-​bəl How to pronounce diagnose (audio) , -​əg-​ , -​zə-​ \ adjective

Examples of diagnose in a Sentence

The test is used to help in diagnosing heart disease. Thousands of new cases have been diagnosed in the past year. The doctor was unable to diagnose the skin condition. a new doctor with little experience diagnosing patients The mechanic was unable to diagnose the problem.
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Recent Examples on the Web For the most part, those intended to diagnose or treat disorders must be proved safe and effective in clinical trials and earn regulatory approval; some may need a doctor's prescription. P. Murali Doraiswamy, Scientific American, "Digital Medicine Can Diagnose and Treat What Ails You," 10 Nov. 2020 In January and February, patients with fevers flooded Wuhan's hospitals, which lacked the manpower, testing kits and medical resources to diagnose and treat them. Nectar Gan, CNN, "Nearly half a million people may have had Covid-19 in Wuhan, study shows. That's almost 10 times the official figure," 29 Dec. 2020 It is named for symptoms originally used to diagnose the condition: Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and development, and Ear abnormalities. Carole Sharwarko, chicagotribune.com, "Frankfort family adapts inflatable display party raising money for CHARGE syndrome research," 20 Dec. 2020 Another hopes to make strides with in-flight medical treatment that could one day be used to diagnose and treat astronauts. Caroline Glenn, orlandosentinel.com, "SpaceX supply mission set to launch this morning with muscle cells from AdventHealth," 6 Dec. 2020 Wisconsin patients and families trust their physicians to diagnose and treat illnesses. Mark Kaufman, Milwaukee Journal Sentinel, "Wisconsin's top physicians at hospitals and health systems have a message: You're the key to fighting COVID-19.," 18 Nov. 2020 There are two main types of tests used to diagnose a COVID-19 infection. Dallas News, "Is rapid coronavirus testing the answer to getting back to normal?," 29 Oct. 2020 Cardiologists often use physical stress tests and electrocardiography to diagnose, treat, and prevent other issues. Zee Krstic, Good Housekeeping, "25 Types of Doctors and What They Do for Patients' Health," 15 Sep. 2020 Hayes’ injury, a torn labrum in his right hip, is one that takes time to fully diagnose. Omari Sankofa Ii, Detroit Free Press, "Detroit Pistons mailbag: Their ceiling, Sekou Doumbouya's minutes and Killian Hayes' injury," 16 Jan. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'diagnose.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of diagnose

circa 1841, in the meaning defined at transitive sense 1a

History and Etymology for diagnose

back-formation from diagnosis

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Time Traveler for diagnose

Time Traveler

The first known use of diagnose was circa 1841

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Statistics for diagnose

Last Updated

17 Feb 2021

Cite this Entry

“Diagnose.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diagnose. Accessed 25 Feb. 2021.

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More Definitions for diagnose



English Language Learners Definition of diagnose

: to recognize (a disease, illness, etc.) by examining someone
: to recognize a disease, illness, etc., in (someone)
: to find the cause of (a problem)


di·​ag·​nose | \ ˈdī-əg-ˌnōs How to pronounce diagnose (audio) \
diagnosed; diagnosing

Kids Definition of diagnose

: to recognize (as a disease) by signs and symptoms The test is used for diagnosing strep throat.


di·​ag·​nose | \ ˈdī-ig-ˌnōs How to pronounce diagnose (audio) , -ˌnōz How to pronounce diagnose (audio) , ˌdī-ig-ˈ, -əg- \
diagnosed; diagnosing

Medical Definition of diagnose

transitive verb

1 : to recognize (as a disease) by signs and symptoms
2 : to diagnose a disease or condition in diagnosed the patient

Other Words from diagnose

diagnosable also diagnoseable \ ˌdī-​ig-​ˈnō-​sə-​bəl, -​əg-​, -​zə-​ How to pronounce diagnose (audio) \ adjective

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