Adrenomedullin is a peptide associated with pheochromocytoma- a tumour arising from adrenal medulla. It was discovered in 1993. Adrenomedullin (AM) is a ubiquitously expressed peptide initially isolated from phaechromyctoma in 1993. Since its first report, studies examining the effects of adrenomedullin have mushroomed, highlighting its role in a number of diseases. Recently a second peptide AM2 has been recognised, exhibiting similar functions.