pathological

IPA/ˌpæθəˈlɒdʒɪkl/
KK[pˌæθəlˈɑdʒɪkəl]IPA/ˌpæθəˈlɑːdʒɪkl/

pathological — adjective

  • pathologicalpositive
  • more pathologicalcomparative
  • most pathologicalsuperlative

1. describing behaviour or a way of thinking that is so extreme, unreasonable, and

1.adjectiveB2
Definition

describing behaviour or a way of thinking that is so extreme, unreasonable, and impossible to control that it seems like a mental health condition — for example, a person who lies constantly even when it causes them harm, or jealousy that destroys every relationship they have

Example

Andrew's pathological jealousy made it impossible for him to trust anyone in a relationship.

pathological + noun describing extreme emotion

Daichi was a pathological gambler who lost his family's savings yet could not stop.

pathological + noun (gambler) for an uncontrollable habit

Common collocations
  • pathological liar
  • pathological gambler
  • pathological jealousy
  • pathological fear
  • pathological need
  • pathological obsession
Synonyms
  • compulsive

    stronger on the uncontrollable urge; common in medical and everyday use

  • obsessive

    focuses on repetitive thoughts rather than behaviour

  • irrational

    broader — any behaviour not based on reason, not necessarily extreme

Antonyms
  • rational

    based on clear thinking and good judgement

  • reasonable

    fair and sensible in everyday conduct

Grammar Patterns

pathological + noun (liar, gambler, jealousy, fear, need)

Usage Note

Frequently appears before nouns describing negative personality traits (liar, gambler, jealousy). The behaviour it describes is not necessarily diagnosed as a medical condition — the word often expresses a strong judgement about how extreme or unhealthy someone's actions are.

Common Mistakes

He has a pathological disease in his lungs.
He has a pathological fear of failure.
Use 'pathological' for extreme behaviour or thinking, not for a physical illness. For physical disease use 'disease-related' or 'caused by disease' (sense 3).

2. relating to the branch of medical science that examines body tissues, fluids, an

2.adjectiveB2
Definition

relating to the branch of medical science that examines body tissues, fluids, and cells to understand the causes and effects of diseases

Example

Mathieu examined the pathological reports from three different hospital labs before making a diagnosis.

pathological report — a formal document from a pathology lab

Gabriel chose a career in pathological research after watching his grandmother recover from cancer.

pathological research — scientific study of disease mechanisms

Common collocations
  • pathological report
  • pathological laboratory
  • pathological anatomy
  • pathological research
  • pathological diagnosis
Synonyms
  • pathologic

    less common variant with the same technical meaning; used in academic writing

Grammar Patterns

pathological + noun (laboratory, report, anatomy, research)

Usage Note

This is the most technical sense, used mainly in medical and academic contexts. The noun form 'pathology' is more common in everyday medical speech (e.g., 'She works in pathology').

Common Mistakes

The doctor sent the blood sample to the pathological department.
The doctor sent the blood sample to the pathology department.
When referring to the hospital department itself, use 'pathology' rather than 'pathological'.

3. caused by or involving a physical disease or illness, especially referring to ch

3.adjectiveB2
Definition

caused by or involving a physical disease or illness, especially referring to changes in the body's tissues or organs that result from illness

Example

Heloísa's blood test showed no pathological changes in her cell counts, to her relief.

pathological + changes — physical alterations from disease

Piotr's doctor explained the pathological effects of long-term smoking on lung tissue.

Common collocations
  • pathological changes
  • pathological condition
  • pathological effects
  • pathological signs
  • pathological process
  • pathological findings
Synonyms
  • diseased

    simpler and more direct; less common in formal medical writing

  • morbid

    scientific term for disease-related; also has an unrelated psychological meaning ('morbid curiosity')

Antonyms
  • healthy

    showing no signs of disease or damage

  • normal

    within the typical range for healthy tissue or function

Grammar Patterns

pathological + noun (condition, changes, effects, signs)

Usage Note

Frequently used in medical reports and academic writing about disease processes. Unlike sense 1, this sense refers only to physical disease — never to behaviour or personality.

Common Mistakes

She has a pathological cough.
The scan showed pathological changes in her lungs.
'Pathological' does not describe symptoms like a cough; it describes changes in the body's structure caused by disease.

Word family

Synonym discussion

Sense: adjective/1

All four words describe behaviour or thinking that deviates from what is normal or reasonable. 'Compulsive' emphasises an uncontrollable urge to act — a compulsive gambler cannot resist gambling despite the consequences. 'Obsessive' focuses on repetitive, intrusive thoughts rather than actions; an obsessive person may think about a fear constantly without acting on it. 'Irrational' is the broadest term, covering any belief or action not based on reason — it is less severe than 'pathological' and does not imply a mental health condition. 'Abnormal' simply means 'different from the norm' and is the most neutral; it can be positive or negative depending on context. For example, a pathological liar invents stories automatically and with no clear benefit, whereas an irrational person might tell a lie once out of fear, and an abnormal test result might just mean an unexpected but harmless finding.

compulsive ↗obsessive ↗irrational ↗abnormal ↗

Common collocations

Nouns

Adverbs

  • pathologically (e.g., pathologically jealous, pathologically honest)

Phrases

  • pathological anatomy
  • pathological diagnosis
  • pathological research
  • pathological science

Etymology

GreekLatinFrenchEnglish

The word comes from Greek 'pathos' (πάθος), meaning 'suffering' or 'disease', combined with '-logia' (λογία), meaning 'study of'. It entered English in the 1600s as a medical term through Latin 'pathologia'. The figurative meaning — describing extreme, uncontrollable behaviour — developed in the 1800s, as doctors and writers began applying medical metaphors to personality traits.

First known use

1656

1656, in the meaning defined at sense 1