A dry mouth is due to decreased secretion of the salivary glands in the mouth. Secretion of the salivary glands (and any gland with external secretion) is controlled by the neuron-vegetative system (sympaticus and parasympaticus). The parasympaticus nervous system increases secretion, while the sympaticus nervous system decreases secretion. Dry mouth can be considered a neurovegetative (sympatic) reaction during a panic attack. Panic attacks are often followed by neurovegetative reactions (tachycardia, dry mouth, sweating etc.) because the neurovegetative system is controlled by the hypothalamus. The hypothalamus is part of the limbic system, which is considered a center of a person's psycho-emotional life.