These symptoms are usually progressive and may be intermittent.Autonomic system dysfunction can occur; in such a case, the patient would complain of orthostatic dizziness, problems breathing, eye, bowel, bladder  and cardiac problems. The patient may also present with a single cranial nerve or peripheral nerve dysfunction.On examination the patients may have weakness, and loss of deep tendon reflexes (rarely increased or normal). There may be atrophy (shrinkage) of muscles, fasciculations (twitching) and loss of sensation. Patients may have multi-focal motor neuropathy, as they have no sensory loss.Most experts consider the necessary duration of symptoms to be greater than 8 weeks for the diagnosis of CIDP to be made. Fatigue has been identified as common in CIDP patients, but it is unclear how much this is due to primary (due to the disease action on the body) or secondary effects (impacts on the whole person of being ill with CIDP). Tests
Typical diagnostic tests include:

Electrodiagnostics – electromyography (EMG) and nerve conduction study (NCS). In usual CIDP, the nerve conduction studies show demyelination. These findings include:a reduction in nerve conduction velocities;
the presence of conduction block or abnormal temporal dispersion in at least one motor nerve;
prolonged distal latencies in at least two nerves;
absent F waves or prolonged minimum F wave latencies in at least two motor nerves. (In some case EMG/NCV can be normal). Serum test to exclude other autoimmune diseases. Lumbar puncture and serum test for anti-ganglioside antibodies. These antibodies are present in the branch of CIDP diseases comprised by anti-GM1, anti-GD1a, and anti-GQ1b.
For example, in the U.S., a single 65 g dose of Gamunex brand in 2010 might be billed at the rate of $8,000 just for the immunoglobulin—not including other charges such as nurse administration.Immunosuppressive drugs are often of the cytotoxic (chemotherapy) class, including rituximab (Rituxan) which targets B cells, and cyclophosphamide, a drug which reduces the function of the immune system. Ciclosporin has also been used in CIDP but with less frequency as it is a newer approach. Ciclosporin is thought to bind to immunocompetent lymphocytes, especially T-lymphocytes.Non-cytotoxic immunosuppressive treatments usually include the anti-rejection transplant drugs azathioprine (Imuran/Azoran) and mycophenolate mofetil (Cellcept). In the U.S., these drugs are used "off-label", meaning that they do not have an indication for the treatment of CIDP in their package inserts. Before azathioprine is used, the patient should first have a blood test that ensures that azathioprine can safely be used.Anti-thymocyte globulin, an immunosuppressive agent that selectively destroys T lymphocytes is being studied for use in CIDP. Anti-thymocyte globulin is the gamma globulin fraction of antiserum from animals that have been immunized against human thymocytes. It is a polyclonal antibody. Although chemotherapeutic and immunosuppressive agents have shown to be effective in treating CIDP, significant evidence is lacking, mostly due to the heterogeneous nature of the disease in the patient population in addition to the lack of controlled trials.A review of several treatments found that azathioprine, interferon alpha and methotrexate were not effective. Cyclophosphamide and rituximab seem to have some response. Mycophenolate mofetil may be of use in milder cases.