The exact pathophysiology of anxiety is unknown. However,
Panic attacks, which include symptoms such as feelings of anxiety, heart palpitations, and sweating can be precipitated by increased noradrenergic neurotransmission.
Extra info: Panic attacks often arise from a small stimulus which can cause enough catecholamine release to precipitate an anxiety attack.
Hypervigilance arises from noradrenergic firing from locus coeruleus.
Extra info: Hypervigilance is another symptom that results from an excess in norepinephrine.
Serotonin dysregulation in the raphe nuclei is associated with anxiety disorders.