It is therefore incorrect to assume that inappropriate AVP release is by definition the sole etiology of hyponatremia, simply because urine is concentrated to a value above 100 mOsmol/kg, as is suggested in several diagnostic hyponatremia guidelines, or even to a value above the plasma osmolality, as is suggested in several others (Ter Maaten et al., 2017–2021; Hoorn et al., 2014; Hoorn & Zietse, 2017; Sterns et al., 2022; Workeneh et al., 2023). Here, AVP is linked to Hyponatremia.