Personal experience with temporary or permanent interruption of adrenergic impulses to brain, heart, kidney, pancreas, and the extemities is reviewed and certain concepts which were formulated long ago are re-emphasized. First, adrenergic blockade unmasks the cholinergic activity of the autonomic nervous system. This is apparent particularly when cardiac, renal, or pancreatic functions are studied under stress. Second, in the immediate treatment of cerebral, cardiac, or digital ischemia, the potentially reversible halo of edema around the irreversible necrosis is rapidly influenced by ganglionic blockade. And third, attention is called to the effect of adrenergic stimulation on sensory nerve endings which develop a higher threshold for pain when sympathetic fibers are interrupted. Although potent drugs inhibiting alpha and beta receptors or the release of catecholamines are widely in use, the obvious advantages of regional vs. systemic interruption of adrenergic impulses is pointed out. When the latter approach is pursued aggressively, the side effects are those of a total sympathectomy.