In patients with suspected chronic inflammatory demyelinating radiculopathy (CIDP), in addition to routine blood tests, blood biochemistry, HIV antibodies, fasting glucose and glycated hemoglobin, and antinuclear antibodies, blood protein electrophoresis or immunofixation electrophoresis should be performed. malignant plasma cell hyperplasia, and more commonly monoclonal globulinopathy of undetermined significance (MGUS). Screening for the most common type of CMT, the peripheral nerve myeloprotein 22 gene, can help to differentiate it from hereditary neuropathies. Also although immune index tests are not very helpful in the diagnosis of CIDP, detection of blood anti-ganglioside GM1 antibodies is of interest. Cerebrospinal fluid examination is important for CIDP, and elevated cerebrospinal fluid protein is found in almost every patient, mostly above 1000 MG/L, with normal cell counts. However, cell counts are elevated in patients with CIDP who have co-infection with HIV. Nerve biopsy is not very helpful in the diagnosis of CIDP because the peroneal nerve, the most commonly taken site, is a distal sensory nerve, whereas the lesions in CIDP are mainly located in motor nerve fibers, nerve roots, and proximal nerve trunks. The main pathologic change on gastrocnemius nerve biopsy is axonal degeneration and loss, probably as a result of proximal nerve inflammatory lesions. Lymphocytic infiltration of the nerve epineurium is common but not specific, so it is not very helpful for diagnosis. Nerve conduction velocity testing confirms the diagnosis in most patients with CIDP. The common denominator of several current electrophysiologic diagnostic criteria is: decreased nerve conduction velocity to less than 80% of the low normal limit if distal motor wave amplitude is normal; prolonged distal motor latency; prolonged F-wave latency; and conduction block or waveform dispersion. the diagnostic criteria for AAN are the presence of three of the above four electrophysiologic abnormalities in two or more nerves to diagnose CIDP. if If the clinical manifestations are consistent with CIDP, but the electrophysiological examination cannot meet the diagnostic criteria of CIDP, then cerebrospinal fluid analysis and nerve biopsy results should be referred to, and experimental treatment can be performed for patients with suspected diagnosis.