bioactive form of Adrenomedullin (ADM), a potent vasodilatory peptide hormone. ADM is produced by various tissues, particularly vascular endothelial and smooth muscle cells, especially in response to stress, inflammation, and hypoxia. In normal physiology, ADM plays a beneficial role in regulating blood pressure, endothelial function, and fluid-electrolyte balance, and it has cytoprotective effects. However, in acute, severe conditions such as septic shock, cardiogenic shock, and severe COVID-19, plasma ADM levels can rise dramatically. This excessive elevation of bioactive ADM is associated with pathological vasodilation, increased vascular permeability (leading to edema and fluid extravasation), myocardial depression, and contributes to the development of refractory hypotension and multiple organ failure.