Autonomic nervous system dysfunction may manifest with a variety of symptoms, with orthostatic intolerance (including orthostatic hypotension or tachycardia) and sweating abnormalities (increased or decreased sweating) being common problems requiring medical evaluation and treatment. Determination of the underlying diagnosis for these symptoms is critical in terms of classification of the disorder and its prognosis. Recent advances in evaluation of patients with these conditions and treatment modalities have enabled physicians to improve overall management of patients with these disorders. These advances include testing for ganglionic acetylcholine receptor antibody in patients with suspected autoimmune autonomic neuropathy and use of pyridostigmine for treatment of patients with orthostatic hypotension or tachycardia.