F51.2Nonorganic disorder of the sleep-wake schedule
Code usage status
Primary diagnosis
May be used as the primary diagnosis
Apply only when it matches the confirmed diagnosis and the documented clinical record.
Specificity
Complete code in the classification
Use when the diagnosis matches and no exclusion applies.
- Chapter V
- Mental and behavioural disorders
- Official Vietnamese name
- Rối loạn lịch trình thức - ngủ không thực tổn
- Additional WHO coding guidance
- A lack of synchrony between the sleep- wake schedule and the desired sleep-wake schedule for the individual's environment, resulting in a complaint of either insomnia or hypersomnia. Psychogenic inversion of: circadian nyctohemeral sleep rhythm Excl.: disorders of the
Related F51 codes
F51
Nonorganic sleep disorders
F51.0
Primary diagnosis candidate
Nonorganic insomnia
F51.1
Primary diagnosis candidate
Nonorganic hypersomnia
F51.3
Primary diagnosis candidate
Sleepwalking [somnambulism]
F51.4
Primary diagnosis candidate
Sleep terrors [night terrors]
F51.5
Primary diagnosis candidate
Nightmares
F51.8
Primary diagnosis candidate
Other nonorganic sleep disorders
F51.9
Primary diagnosis candidate
Nonorganic sleep disorder, unspecified
Clinical record checklist
View coding guide →- Confirm that the code matches the final documented diagnosis.
- Use one primary-diagnosis code and record only relevant additional conditions.
- Review Ministry indicators, inclusions, exclusions and notes.
- Do not infer a diagnosis beyond the clinical record.
2026 regulatory basis
Indicators are taken from columns 24–29 of the classification accompanying Circular 06/2026/TT-BYT, cross-referenced with Decision 1849/QĐ-BYT and Official Dispatch 4059/BYT-BH.
