Guillain-Barré synrome (GBS) (in French pronounced [ɡilɛ̃ baˈʁe], in English pronounced /ˈɡiːlæn ˈbɑreɪ/, /ɡiːˈæn bəˈreɪ/,etc.) is an acute, autoimmune, polyradiculoneuropathy affecting the peripheral nervous system, usually triggered by an acute infectious process. It is included in the wider group of peripheral neuropathies. There are several types of GBS, but unless otherwise stated, GBS refers to the most common form, acute inflammatory demyelinating polyneuropathy (AIDP). It is frequently severe and usually exhibits as an ascending paralysis noted by weakness in the legs that spreads to the upper limbs and the face along with complete loss of deep tendon reflexes. With prompt treatment by plasmapheresis or intravenous immunoglobulins and supportive care, the majority of patients will regain full functional capacity. However, death may occur if severe pulmonary complications and dysautonomia are present.