Category · F90-F98 block
F90 — Hyperkinetic disorders
Terminology note: ICD-10's "hyperkinetic disorder" and DSM-5/ICD-11's "attention deficit hyperactivity disorder" (ADHD) describe overlapping territory, but they are not identical: ICD-10's hyperkinetic disorder requires more severe, pervasive impairment across both inattention and overactivity/impulsiveness together, evident in more than one situation, than DSM-5's broader ADHD criteria (which allow a predominantly-inattentive presentation with no significant hyperactivity). This page uses ICD-10's own term and criteria throughout, while noting this mapping so a reader familiar with "ADHD" is not misled into assuming the two terms are simple synonyms.
What is this category?
F90 covers disorders characterised by an early onset (usually within the first five years of life), a combination of overactive, poorly modulated behaviour with marked inattention and lack of persistent task involvement, and these features being pervasive over situations and persistent over time, not explained by another disorder such as autism or an anxiety state.
Core diagnostic concept
F90 requires inattention (failing to sustain attention on tasks or play, not following through on instructions, being easily distracted) together with overactivity and impulsiveness (excessive running or climbing in situations where it is inappropriate, difficulty waiting turns, blurting out answers), evident before age 6, and — decisively — evident in more than one situation (for example, both at home and at school), not confined to one setting alone.
Key diagnostic features
- Inattention
- Fails to sustain attention on tasks or play activities, appears not to listen, does not follow through on instructions, is easily distracted by extraneous stimuli.
- Overactivity
- Excessive running or climbing in situations where it is inappropriate, or excessive fidgeting/restlessness, well beyond what would be expected for the child's developmental level.
- Impulsiveness
- Frequently blurts out answers before questions are completed, has difficulty waiting turns, often interrupts or intrudes on others.
- Cross-situational pervasiveness
- The pattern is evident in more than one situation (for example, both at home and at school), not confined to a single setting or relationship.
How to weigh evidence
These learning labels are teaching aids, not official ICD-10 terminology (see Sources and Method).
- supports A 6-year-old's teacher and parents independently describe the same pattern of restlessness, difficulty sustaining attention, and impulsive answering, present since before school age, at home and at school alike.
- consistent not decisive A parent describes their child as 'always on the go' with no further detail on attention, impulsiveness, or whether the pattern appears anywhere besides home.
- raises alternative A child is restless and inattentive only in one particular, unusually chaotic and understimulating classroom, with no such pattern reported at home or in other settings — pointing toward a situational response rather than F90.
- contradicts or weakens The overactivity and distractibility appear only during a period of acute family stress and resolve within weeks once the stressor passes — inconsistent with F90's required persistence over time.
- missing and necessary to ask Whether the pattern has been confirmed by an independent observer in a second setting (school as well as home), and how early it was first noticed.
Diagnostic boundary
F90 is distinguished from F91 (conduct disorders) by which feature is primary: attention/activity regulation difficulty in F90, versus a persistent pattern of rule-violating, aggressive, or defiant conduct in F91 — though the two frequently co-occur (F90.1). It is distinguished from ordinary high-energy childhood behaviour by degree, cross-situational pervasiveness, and functional impairment, and from an anxiety-driven restlessness (F93) by the absence of a specific fear or worry driving the activity.
Full comparisons:
Duration and course
Minimum duration: Onset before age 6 is required; the pattern must also be persistent over time, not a brief or recent change.
Course: Features often continue in some form into adolescence and adulthood, though presentation and impairment can change with development and support.
Included presentations
- A combination of inattention, overactivity, and impulsiveness, evident before age 6, present in more than one situation, and persistent over time.
Exclusions and distinguishing presentations
| If this is true instead… | Consider | Why |
|---|---|---|
| Restlessness and distractibility confined to a single chaotic or understimulating setting, with no such pattern elsewhere | No specific code — see reasoning | Without evidence from more than one setting, the cross-situational pervasiveness F90 requires is not established — a situational explanation should be considered first. |
| Overactivity and social/communication difficulty together with restricted, repetitive behaviour | F84 | When the fuller pervasive-developmental triad is present, F84 is the more accurate classification; attention and activity difficulties frequently co-occur with F84 and can be coded alongside it when both are genuinely present. |
Four-character subtypes (orientation)
The fourth character records whether a co-occurring conduct disorder is also present (F90.1) or not (F90.0) — it is not a severity scale, and a child's degree of impairment does not by itself decide which fourth character applies.
- F90.0 — Disturbance of activity and attention
- The core hyperkinetic pattern — inattention, overactivity, and impulsiveness — without a co-occurring conduct disorder. (in_depth)
- F90.1 — Hyperkinetic conduct disorder
- The F90.0 pattern together with a co-occurring conduct disorder meeting F91's own criteria — both patterns must independently be present, not merely disruptive behaviour arising from inattention alone. (in_depth)
- F90.8 — Other hyperkinetic disorders
- A hyperkinetic pattern not fitting F90.0 or F90.1. (taught for orientation only, not separately assessed in this pilot)
- F90.9 — Hyperkinetic disorder, unspecified
- Insufficient information to specify further; a residual category, not a default for a vignette that simply requires closer reading. (taught for orientation only, not separately assessed in this pilot)
External causes to check first
Categories in this block require that the disturbance is not better explained by another external cause listed below. These short capsules are reminders, not full teaching modules.
Diagnostic principle capsule — Cross-situational pervasiveness
A shared reminder that F90 (hyperkinetic disorders) and F91 (conduct disorders) each turn, in part, on whether a behavioural pattern is confirmed across more than one setting or context, rather than confined to a single relationship, classroom, or household — though the two categories use this principle for different purposes: F90 requires cross-situational pervasiveness as a core, decisive diagnostic feature in its own right, while F91's fourth character (F91.0 confined to the family versus F91.1/F91.2 extending into peer and community life) uses setting information to describe the pattern's scope once a persistent conduct disturbance is already established.
What to check:
- Whether the behavioural pattern has been independently confirmed by more than one observer in more than one setting (for example, both a parent and a teacher, describing both home and school), rather than resting on a single informant's account of a single context.
- Whether a pattern confined to one unusually chaotic, understimulating, or high-conflict setting might instead reflect a situational response to that specific environment, rather than a pervasive, cross-situational pattern.
- For F91 specifically, that setting confirms scope (family-confined versus extending into peer and community life) only after a persistent conduct-disorder-level pattern is already established — it does not by itself establish that the pattern exists.
- That a single classroom's report, however detailed, is not sufficient on its own to confirm cross-situational pervasiveness — corroborating evidence from a second, independent setting should be sought before concluding the pattern is pervasive.
A full multi-informant clinical assessment gathering independent accounts from parents, teachers, and other caregivers across all the settings relevant to a child's daily life, which a single vignette can only approximate.
Common learner errors
Worked example — one setting, or more than one?
An 8-year-old boy's teacher reports he is constantly out of his seat, cannot wait his turn, and rarely finishes assigned work. His parents, when asked, say he is 'a bit of a handful' at home but manage his behaviour without much difficulty, and no comparable pattern has been reported by his grandparents, who care for him most weekends.
- Step 1 — Check the core features: out-of-seat behaviour, difficulty waiting turns, and not finishing work are consistent with overactivity, impulsiveness, and inattention.
- Step 2 — Check cross-situational pervasiveness specifically: the pattern is clearly documented at school, but at home it is described only as 'a bit of a handful,' and it is absent during weekends with grandparents.
- Step 3 — Weigh what this means: F90 requires the pattern to be evident in more than one situation; here, only one setting (school) shows a clear, impairing pattern.
- Conclusion — Before F90 can be confirmed, a more detailed history from home and other settings is needed; on the information given so far, cross-situational pervasiveness is not yet established.
Interactive practice
- Type A Restless everywhere he goes Recognition · Foundational
- Type B Impulsive rule-breaking, or a conduct pattern? Boundary discrimination · Intermediate
- Type B Restless in one classroom only Boundary discrimination · Transfer
Retrieval prompts
Try answering each of these from memory before revealing where to check. Nothing you think or type here is sent or saved anywhere.
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Name the three core feature domains of F90.
Reveal answer location
Check Duration and course, Diagnostic boundary, or the rapid revision card below — the cue you need is one of those, in this category's own already-authored wording.
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Explain why evidence from only one setting is not enough to confirm F90.
Reveal answer location
Check Duration and course, Diagnostic boundary, or the rapid revision card below — the cue you need is one of those, in this category's own already-authored wording.
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Explain the difference between F90.0 and F90.1.
Reveal answer location
Check Duration and course, Diagnostic boundary, or the rapid revision card below — the cue you need is one of those, in this category's own already-authored wording.
These self-checks are a personal study aid only, visible to you on this page for this visit — they are not stored and do not affect your mastery dimensions.
Rapid revision card
F90: Inattention, overactivity, and impulsiveness, evident before age 6 and pervasive across more than one setting — not a single-classroom pattern.
Decisive boundary cues:
- Confirmed in more than one setting (e.g. home and school) -> weighs toward F90.
- Confined to one chaotic or understimulating setting only -> weighs toward a situational explanation, not F90.
- Full pervasive-developmental triad also present -> weighs toward also considering F84.
Duration/course: Onset before age 6, persistent over time — not a recent or brief change.
Nearest alternatives: F91, F84, F93
Common mistake: Confirming F90 from a single setting's report alone, without checking for corroborating evidence from a second setting.
Retrieval prompt: What second source of information would you need before confirming this is pervasive across situations?
(or use your browser's print function) Open full-page printable revision view →
Related glossary terms
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Hyperkinetic disorder
ICD-10's term for a disorder combining inattention with overactivity and impulsiveness, evident before age 6 and pervasive across more than one setting. Overlaps with, but is not identical to, DSM-5/ICD-11's broader 'attention deficit hyperactivity disorder' (ADHD), which permits a predominantly-inattentive presentation without significant hyperactivity.
Source basis
WHO ICD-10 international classification structure and code/title (ICD-10 Browser, 2019 English release).
Original educational synthesis, informed by general published clinical-education understanding of ICD-10 F90-F98; no verbatim CDDG or DCR text is reproduced. See Sources and Method for the full policy.
Last reviewed: 2026-09-17. Full policy: Sources and Method.
Educational resource only. This page and its cases teach ICD-10 classification reasoning using fictional scenarios. It does not diagnose real people and should not be used to assess yourself or anyone else. If you are concerned about a child's development, behaviour, or emotional wellbeing, please speak with a qualified professional for assessment and support.