'salud' originates from Latin, specifically the word 'salus' (genitive 'salutis'), where the root meant 'health, safety'.

'salus' passed into Old Spanish as 'salud', retaining the sense of health and well-being, and appears in Medieval Spanish texts as 'salud'.

Initially, it meant 'health; safety' in Latin, and over time it has kept that core meaning in modern Spanish while also developing the pragmatic use as a toast meaning 'to your health'.