ICD-10 Code for Syncope (Passing Out)
The ICD-10 code for a patient passing out (syncope) is R55, which represents "Syncope and collapse." 1, 2
Understanding the Code
- R55 is the primary ICD-10 code used to classify syncope, defined as transient loss of consciousness due to cerebral hypoperfusion with spontaneous return to baseline function 3, 4
- This code specifically captures episodes where the patient experiences complete, transient loss of consciousness with rapid onset, short duration, spontaneous recovery, and loss of postural tone 5
Clinical Context for Proper Coding
Before assigning R55, verify the episode meets syncope criteria by confirming:
- Loss of consciousness was complete and transient 5
- Onset was rapid with short duration 5
- Recovery was spontaneous, complete, and without sequelae 5
- Patient lost postural tone during the episode 5
If any of these features are absent, consider alternative diagnoses before using R55, as the episode may represent seizure, stroke, or other non-syncopal causes of transient loss of consciousness 6, 4
Diagnostic Accuracy Considerations
- The ICD-9 equivalent (code 780.2) demonstrated moderate sensitivity of 63% but high specificity of 98% for identifying true syncope cases 1
- This means R55 may undercode actual syncope cases but when assigned, it reliably indicates syncope rather than other conditions 1
- Approximately 48% of patients discharged with syncope codes have unexplained etiology even after extensive workup, reflecting the diagnostic challenge 2
Additional Coding Guidance
Consider more specific codes when the underlying cause is identified:
- Use cardiac-specific codes (I codes) when arrhythmia or structural heart disease is documented as the cause 5
- Use I95.1 for orthostatic hypotension when documented as the mechanism 5
- Use appropriate codes for situational syncope variants (e.g., micturition, defecation, cough syncope) when identified 5
R55 should be the primary diagnosis code when:
- Syncope is the chief complaint and reason for encounter 2
- The underlying etiology remains unexplained after initial evaluation 2
- The episode meets clinical criteria for true syncope rather than other causes of transient loss of consciousness 5, 4
Common Coding Pitfalls to Avoid
- Do not use R55 for presyncope or near-syncope without actual loss of consciousness 7
- Avoid using R55 for seizures (use G40-G41 codes instead), which typically have longer duration of unconsciousness (>1 minute), lateral tongue biting, and post-ictal confusion 8, 6
- Do not code as syncope if the patient has focal neurological findings suggesting stroke or TIA 8
- Distinguish from psychogenic pseudosyncope which may require different coding 8