G56.4Non-Billable (Header)Causalgia of upper limbExcludes 1 — Do NOT code togethercomplex 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-)reflex sympathetic dystrophy of upper limb (G90.51-)Child CodesG56.40Causalgia of unspecified upper limbG56.41Causalgia of right upper limbG56.42Causalgia of left upper limbG56.43Causalgia of bilateral upper limbsCode Hierarchy└G56Mononeuropathies of upper limb└G56.4Causalgia of upper limb└G56.4Causalgia of upper limb