diagnosis

American  

[dahy-uhg-noh-sis] / ˌdaɪ əgˈnoʊ sɪs /

noun

diagnoses plural

1. Medicine/Medical.

   1. the process of determining by examination the nature and circumstances of a diseased condition.

   2. the decision reached from such an examination. Dx

2. Biology. scientific determination; a description that classifies a group or taxon precisely.

3. a determining or analysis of the cause or nature of a problem or situation.

4. an answer or solution to a problematic situation.

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diagnosis British  

/ ˌdaɪəɡˈnəʊsɪs /

noun

1. 1. the identification of diseases by the examination of symptoms and signs and by other investigations

   2. an opinion or conclusion so reached

2. 1. thorough analysis of facts or problems in order to gain understanding and aid future planning

   2. an opinion or conclusion reached through such analysis

3. a detailed description of an organism, esp a plant, for the purpose of classification

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diagnosis Scientific  

/ dī′əg-nō′sĭs /

diagnoses plural

1. The identification by a medical provider of a condition, disease, or injury made by evaluating the symptoms and signs presented by a patient.

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Usage

Plural word for diagnosis The plural form of diagnosis is diagnoses, pronounced [ dahy-uhg-noh-seez ]. The plurals of several other singular words that end in -is are also formed in this way, including hypothesis/hypotheses, crisis/crises, and axis/axes. A similar change is made when pluralizing appendix as appendices. Irregular plurals that are formed like diagnoses derive directly from their original pluralization in Latin and Greek.

Commonly Confused

Although diagnosis and prognosis are both very familiar medical terms, they are sometimes used interchangeably (by nonmedical people), as if they were synonymous words. They are not. When a person is unwell and asks a doctor what is wrong with them, what they are asking for is a diagnosis. Examining the symptoms, as with a thermometer or stethoscope, and evaluating the results of a procedure such as a throat culture, blood test, or x-ray will help the doctor identify the patient’s illness. Whatever that ailment may be, the identification, or naming of it, is the diagnosis. The diagnosis of rheumatoid arthritis was very disheartening. The diagnosis is an acute case of tendinitis. Once a patient has been given a diagnosis, the next thing they’ll want to know is what sort of an outcome they can expect, which means they want to know the prognosis. Unlike diagnoses, which are conclusively based on tangible evidence, prognoses are reasonable predictions based on past observations of similar cases. A prognosis gives the patient an idea of what to expect about the course of their illness, including the probability of recovery. As ailments range from the most superficial to the most life-threatening, it is typical for the word prognosis to be qualified by such adjectives as excellent, favorable, good, positive, negative, poor, dire, grim. Doctors will never tire of telling us, “Early detection and treatment are your best bets for a positive prognosis.” And no one wants to say, “The prognosis was so poor that he could no longer hide his condition from his family.” In nonmedical contexts, diagnosis still carries its meaning of naming or identifying something, especially when that involves a situation or problem. When our computer kept crashing, the tech said that nearby UFO activity could be the reason, so we got another tech—and a proper, earthbound diagnosis! Likewise, prognosis is used outside of medical contexts, retaining its meaning of reasonable prediction. As a lover of pesticide-free smoothies, I’m pleased to say that the prognosis for the future of organic farming has never been better.

Other Word Forms

Derived Forms

• prediagnosis
  noun

Inflected Forms

Nouns

• diagnoses
  plural

Etymology

Origin of diagnosis

First recorded in 1675–85; from New Latin, from Greek diágnōsis “a distinguishing, means or power of discernment”; see dia-, -gnosis

Explanation

When a doctor tells you why you're feeling ill, he gives you a diagnosis. He asks questions, checks your symptoms, and then identifies what's making you sick. Diagnosis is a medical term, but you can diagnose lots of things: problems in a relationship, a coming economic crisis, or the reason the car won't start. If you have a sore throat, runny nose and a bad cough, most of the time doctors will diagnose a cold. If the car won't start and the lights and radio are also off, the diagnosis is simple: your battery’s dead. Anytime you determine the cause of a problem, you give a diagnosis.

Example Sentences

See Examples For:

diagnosis diagnoses

Some people who cannot move or communicate may still retain conscious brain activity, making reliable detection methods potentially important for diagnosis, treatment, and decisions about medical care.

From Science Daily ● Jul. 30, 2026

“A lot of nervousness,” Hernández said about playing again, mentioning that he had a panic attack when first learning of his worse-than-expected diagnosis.

From Los Angeles Times ● Jul. 29, 2026

Williams said many people never seek testing, while others miss the short window needed for the most accurate diagnosis.

From BBC ● Jul. 29, 2026

First of all, I’m sorry about your stepdad’s diagnosis.

From MarketWatch ● Jul. 28, 2026

I access her history and am shocked to realize that she’s gotten this far without any notice, without any diagnosis.

From "Every Day" by David Levithan

Researchers examined whether total fructose intake and the consumption of sugar-sweetened beverages, fruit juice and whole fruit were associated with self-reported diagnoses of high blood pressure.

From Science Daily ● Jul. 23, 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

AI can provide earlier and more accurate medical diagnoses, together with treatment plans providing real advancements for underserved communities.

From The Wall Street Journal ● Jul. 9, 2026

Oskamp found that as he gave the psychologists more and more information about Kidd, their confidence in the accuracy of their diagnoses increased dramatically.

From "Blink" by Malcolm Gladwell

Related Words

• analysis
• conclusion
• examination
• interpretation
• investigation