'hypoglycemic' ultimately derives from New Latin 'hypoglycaemic(us),' formed from Greek elements.

'hypoglycemic' comes from New Latin 'hypoglycaemicus' (19th century medical Latin), from Greek 'hypo-' ('under, below'), Greek 'glykys' ('sweet') combined with a form related to 'haima' ('blood'), producing a term meaning 'below sweet blood' (i.e., low blood sugar); this then entered English as 'hypoglycemic'.

Initially used in medical Latin to denote conditions 'of low blood sugar'; over time it became the standard English adjective (and occasional noun) describing either the state of low blood sugar or agents that cause/relate to it.