Prognosis vs. Diagnosis?

A diagnosis is the determination of a disease or ailment. A prognosis is the predicted outcome of a condition.

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What is the difference between prognosis and diagnosis?

The nouns prognosis and diagnosis are both medical terms we use to discuss health issues. If a doctor provides a medical diagnosis, a medical prognosis typically follows. But we don’t always use these terms for health care topics, so it’s easy to see why these nouns are easily confused. 

In general, the word diagnosis means ‘the identification of a disease or medical condition,’ although the noun can describe any investigation and characterization of several different subjects. This is particularly true for related terms such as diagnose (verb) and diagnosable (adjective). For example, 

  • “The bright side: once you can diagnose the issue, you can resolve it and move into the new frontier of your company.” –– Forbes
  • “It’s no wonder that almost everyone who has heard of the musical is diagnosable with “Hamilton fever.” –– The Commentator 

The noun prognosis is similar to diagnosis, except it means ‘the likely outcome of a disease or circumstance.’ And similarly to diagnosis, we’re likely to see the noun in various contexts through terms like prognostic (adjective) and prognosticate (verb). For example, 

  • “Let’s prognosticate during a pandemic-impaired college football season teetering toward farce.” –– The Washington Post
  • “Among both inflammatory markers of interest and previously established prognostic factors, the PNI was the only factor to emerge….” –– Onco’Zine

In summary, we can count on a diagnosis and a prognosis to make a conclusion about a current condition. The difference is that a prognosis is the predicted outcome of a diagnosis

What does diagnosis mean?

The noun diagnosis (plural ‘diagnoses’) is essentially a conclusion made after a thorough examination. As paraphrased by the New Oxford American Dictionary, a diagnosis is:

  1. ‘The identification of an illness or problem by the examination of disease traits and symptoms,’ or; 
  2. ‘The investigation and distinct characterization of a biological genus, species, disease, or other phenomena’ (“Diagnosis” 479).  

How to use diagnosis in a sentence?

  • “Doctors follow-up a diagnosis with a prognosis to ensure the best possible outcome for survival.” 
  • “Patients may receive a late diagnosis of lung cancer because there were no early-stage symptoms.” 
  • “High-quality x-rays may allow doctors to provide a faster diagnosis of COVID-19.” 
  • “It is challenging for many people to accept a diagnosis of anxiety and depression.” 


Call, conclusion, consensus, decree, finding, instruction, last word, mandate, ruling, word.

What does prognosis mean?

In the context of medical terminology, the noun prognosis (plural ‘prognoses) means ‘a prospect of recovery’ expected from a particular disease or medical circumstance. However, the word also means ‘forecast’ or ‘prediction’ for topics such as sports, business, and politics. 

How to use prognosis in a sentence?

  • “It is too early to give an economic prognosis of the coronavirus pandemic.” 
  • “An early diagnosis of breast cancer improves one’s prognosis.” 
  • “A biopsy can determine the presence of any type of cancer and provide a more accurate prognosis for individual patients.” 
  • “The prognosis of the sickly stock market prompted many Americans to occupy the city of New York for months on end.”  


Augury, bodement, forecast, foretelling, foresight, harbinger, prediction, prognostic, prognosticating, prognostication, prophecy, prospectus, sign, soothsaying.

Where do the words diagnosis and prognosis come from?

Diagnosis is a late 17th-century noun from Latin via Greek diagnōsis (‘discernment’) and diagignōskein (‘to distinguish’). For either term, the prefix dia- means ‘apart,’ and gignōskein means ‘recognize’ and ‘know’ (“Diagnosis” 479). 

The noun prognosis also emerged in the 17th century, but through Latin prognōsis and Greek progignōskein (‘to foreknow’). Greek progignōskein consists of pro- for ‘before’ and gignōskein for ‘know’ (“Prognosis” 1395). 

Another interesting feature of diagnosis and prognosis involves the use of “gnosis,” the Greek noun for “knowledge.” According to the Online Etymology Dictionary, Greek gnosis also means “special knowledge of spiritual mysteries,” which makes sense considering how Gnosticism involves collecting religious ideologies and practices. 

What are examples of a medical diagnosis and prognosis?

Now that we have a general understanding of the terms diagnosis and prognosis, it’s time to answer a common question: “what does a medical diagnosis or prognosis look like?” 

Four common diagnoses include diseases like diabetes, anxiety, hypothyroidism, or osteoarthritis. However, severe ailments discussed in the news often involve various cancers, congestive heart failure, Alzheimer’s Disease, Amyotrophic Lateral Sclerosis (ALS), or Parkinson’s Disease. 

As we already know, a prognosis is the prediction of disease outcome, so every prognosis varies by disease onset and severity, a patient’s medical history, the availability of treatment, etc. 

Example diagnosis and prognosis for General Anxiety Disorder

For a licensed practitioner to diagnose someone with General Anxiety Disorder (GAD), a patient would need to report symptoms outlined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) for at least six months. 

According to American Family Physician, the DSM-5’s diagnostic criteria for GAD includes: 

  1. Excessive anxiety and worry surrounding everyday events or activities. 
  2. The inability to control one’s worries.
  3. Feelings of anxiety and worry co-exist with at least three symptoms (but not longer than six months) involving: restless, chronic fatigue, irritability, muscular tension, and difficulties concentrating or sleeping. 
  4. Mental and physical symptoms cause clinically significant distress or impair the function of one’s social and occupational lives. 
  5. Disturbances related to symptoms do not arise from chemical substances or other medical conditions. 
  6. Disturbances are not indicative of other psychological disorders with prevailing symptoms of GAD. 

If a patient meets all criteria for GAD, a practitioner can diagnose them and provide a treatment plan. The prognosis of GAD is entirely dependent on the accuracy of diagnosis, the effectiveness of treatment, and how well a treatment plan coincides with the patient’s current condition and their ability to adhere. 

According to Harvard Health Publishing, the prognosis for GAD has a good “outlook,” and, “with appropriate treatment, about 50% of patients improve within 3 weeks of starting treatment, and 77% improve within 9 months.” 

Additional reading: diagnosis vs. prognosis

Looking for more health-related grammar topics? The Word Counter has your back. Check out our lessons on topics, such as: 

Test Yourself!

Before you diagnose your understanding of diagnosis vs. prognosis, test how much you’ve learned with the following multiple-choice questions. 

  1. True or false: we can only use the words diagnosis and prognosis for medical contexts.
    a. True
    b. False
  2. Which comes first: a diagnosis or prognosis? 
    a. Diagnosis
    b. Prognosis
  3. The prediction of the course of a disease is called a ____________. 
    a. Diagnosis
    b. Prognostic 
    c. Diagnostic
    d. Prognosis 
  4. ____________ is the determination of the nature of a disease. 
    a. Diagnosis
    b. Prognostic
    c. Diagnostic
    d. Prognosis
  5. Understanding a patient’s current condition is vital for providing a ____________.
    a. Diagnosis
    b. Prognostic
    c. Prognosis 
    d. A and C
  6. Question
    a. Answer
    b. Answer
    c. Answer
    d. Answer


  1. B
  2. A
  3. D
  4. A
  5. D


  1. Burns, Stephanie. “How To Diagnose Problems Keeping You From The Next Stage Of Business.” Forbes, 23 May, 2020. 
  2. “Diagnosis.” The New Oxford American Dictionary, 3rd ed., Oxford University Press, 2010, p. 479.
  3. Garcia, Danielle. “Pro-Inflammatory Response may Identify Cancer Patients at Risk of Adverse Outcomes from COVID-19.” Onco’Zine, 22 Nov 2020. 
  4. Generalized Anxiety Disorder.Harvard Health Publishing, Harvard Medical School, Dec 2018. 
  5. Harper, Douglas. “Gnosis (n.).” Online Etymology Dictionary, Etymonline, 2020. 
  6. Locke, Amy B., et al. “Diagnosis and Management of Generalized Anxiety Disorder and Panic Disorder in Adults.” American Family Physician, PubMed, 1 May 2015.
  7. Prognosis.” The American Heritage Dictionary of the English Language, 5th ed., Houghton Mifflin Harcourt Publishing Company, 2020. 
  8. “Prognosis.” The New Oxford American Dictionary, 3rd ed., Oxford University Press, 2010, p. 1395.   “Prognosis.” The Dictionary, Merriam-Webster Inc., 2020.