'hypochondriacal' originates from Greek via Latin and French, specifically from the Greek noun 'hypochondria' where the prefix 'hypo-' meant 'under' and 'chondrion' meant 'cartilage' (later used for the region below the ribs).

'hypochondriacal' developed from Greek 'hypochondria' → Late Latin/Medieval Latin 'hypochondria' → Middle English/French forms, where the noun denoting the rib region and then the illness gave rise to the adjective form 'hypochondriacal'.

Initially it referred to the anatomical region 'below the ribs'; over time it came to denote the condition of excessive health anxiety, and the adjective now means 'pertaining to hypochondria' or 'characterized by excessive worry about health'.