ICD-10 Code G56.4 – Causalgia of upper limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G56.4 – Causalgia of upper limb
What it is
G56.4 identifies causalgia of the upper limb, a neuropathic pain condition affecting an arm or hand after nerve injury. Use it when documentation specifically names causalgia or a similar post-injury burning pain syndrome.
Clinical signs
Typical findings include severe burning pain, marked tenderness, and pain out of proportion to the injury. Clinical features vary; refer to documentation for sensory changes, swelling, or autonomic symptoms.
When to use this code
Use G56.4 when the provider documents causalgia in the upper extremity, including the arm, forearm, wrist, or hand. It may apply after trauma, surgery, or other nerve damage if the diagnosis is clearly stated. If the record only says neuropathic pain, check documentation.
Do not use for
Do not use this code for generalized limb pain without a documented causalgia diagnosis. It is also not the right choice for lower-limb causalgia or unspecified neuropathy.
Coding tip
Query the provider if the note describes burning nerve pain but does not clearly identify causalgia or the affected limb.