F51.5 ICD-10-CA code: Nightmares
F51.5 is the ICD-10-CA code for “Nightmares” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
F51.5Nightmares
ICD-10-CA · Canada · Also written F515
Index terms
Entries in CIHI’s alphabetical index that lead to F51.5. Searching the index by the condition the note names is how coders reach this code.
- Disorder (of), nightmare
- Disorder (of), dream anxiety
Notes for F51.5
As CIHI prints them, with any note F51.5 takes from the headings above it.
Includes
- Dream anxiety disorder
- Disorders of psychological developmentFrom Chapter 5: Mental and behavioural disorders (F00-F99)
Excludes
Conditions classified elsewhere.
- Sleep disorders (organic) (G47.-)From F51 Nonorganic sleep disorders
- Symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)From Chapter 5: Mental and behavioural disorders (F00-F99)
Note
- Dream experiences loaded with anxiety or fear. There is very detailed recall of the dream content. The dream experience is very vivid and usually includes themes involving threats to survival, security, or self-esteem. Quite often there is a recurrence of the same or similar frightening nightmare themes. During a typical episode there is a degree of autonomic discharge but no appreciable vocalization or body motility. Upon awakening the individual rapidly becomes alert and oriented.
- In many cases, a disturbance of sleep is one of the symptoms of another disorder, either mental or physical. Whether a sleep disorder in a given patient is an independent condition or simply one of the features of another disorder classified elsewhere, either in this chapter or in others, should be determined on the basis of its clinical presentation and course as well as on the therapeutic considerations and priorities at the time of the consultation. Generally, if the sleep disorder is one of the major complaints and is perceived as a condition in itself, the present code should be used along with other pertinent diagnoses describing the psychopathology and pathophysiology involved in a given case. This category includes only those sleep disorders in which emotional causes are considered to be a primary factor, and which are not due to identifiable physical disorders classified elsewhere.From F51 Nonorganic sleep disorders
Where F51.5 sits
- 1ChapterChapter 5: Mental and behavioural disorders (F00-F99)
- 2Block F50-F59Behavioural syndromes associated with physiological disturbances and physical factors
- 3Category F51Nonorganic sleep disorders
- 4Valid code F51.5Nightmares
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code F51.5 mean?
F51.5 is the ICD-10-CA code for “Nightmares” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is F51.5 in ICD-10-CA?
F51.5 sits under F51 Nonorganic sleep disorders, within F50-F59 Behavioural syndromes associated with physiological disturbances and physical factors, within Chapter 5: Mental and behavioural disorders (F00-F99).
What coding notes apply to F51.5?
ICD-10-CA lists Note, Includes, Excludes notes for F51.5, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.