The diagnosis of polyneuropathy is established through a holistic evaluation, including the patient's symptoms, a comprehensive clinical examination, laboratory tests, and an electromyography (EMG) study. EMG is considered an indispensable diagnostic method for polyneuropathy. During this procedure, low-dose electrical stimuli are applied to the patient's arms and legs via surface electrodes to assess the function and health of peripheral nerves. This allows for the examination of important parameters such as nerve conduction velocity, the integrity of the myelin sheath, and the overall electrical activity of the nerves. When deemed necessary, needle electrodes may also be used during the EMG test to directly evaluate the condition of the muscles to clarify the differential diagnosis.