The function of the autonomic nervous system is divided so that the parasympathetic system spares central nervous system energy and the sympathetic system makes extra energy available and consumes it. The sympathetic nervous system then prepares our body for emergency and it always functions when our conscious or even unconscious mind notices a need for defence or to provide energy. A surgical procedure, where the upper thoracic sympathetic ganglions are ablated, either with cauterization or clamping with metallic clips, has been used to treat sweating of the hands and facial blushing for decades. Instead of ablating large areas of sympathetic trunk, which can cause severe side-effects such as reflex sweating of the body, the surgical procedure is nowadays carried out in a more precise symptom-mediating level of uppermost thoracic sympathetic ganglia. Blushing, hyperhidrosis of palms and head, and trembling are common in social phobia, and they seem to be provoked by the activation of the sympathetic nervous system. Preliminary studies show that some social phobia patients may benefit from the endoscopic sympathetic block (ESB). If the patient with generalized social phobia has not received help with adequate medication or psychotherapy, the ESB may be a new possible treatment of choice.