familial tremor (essential tremor) (BFT) is responsive to peripheral ? adrenergic blockers, and ?₂-stimulation is known to cause tremor. Patients with BFT were found to have increased plasma adrenaline but not noradrenaline.

Low or absent concentrations of adrenaline can be seen in autonomic neuropathy or following adrenalectomy. Failure of the adrenal cortex, as with Addison's disease, can suppress adrenaline secretion as the activity of the synthesizing enzyme, phenylethanolamine-''N''-methyltransferase,