G56.4Causalgia of upper limb

G56.4 is the ICD-10-CM diagnosis code for Causalgia of upper limb. It belongs to category G56 (mononeuropathies of upper limb), block G50-G59 (nerve, nerve root and plexus disorders) and chapter 6 (diseases of the nervous system). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.

Within G56 (mononeuropathies of upper limb), G56.4 is specifically for Causalgia of upper limb. Related codes cover carpal tunnel syndrome (G56.0), other lesions of median nerve (G56.1), lesion of ulnar nerve (G56.2), lesion of radial nerve (G56.3), other specified mononeuropathies of upper limb (G56.8) and unspecified mononeuropathy of upper limb (G56.9).

To report this condition, pick the subcode that matches the documentation: G56.40 (limb), G56.41 (limb), G56.42 (limb) and G56.43 (limbs).

Don't report G56.4 together with the conditions in its Excludes1 note: complex regional pain syndrome I of lower limb (G90.52-), complex regional pain syndrome I of upper limb (G90.51-), complex regional pain syndrome II of lower limb (G57.7-), reflex sympathetic dystrophy of lower limb (G90.52-) and 1 more.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.