Fetching details from the dictionary...
constitution (physical); physical make-up; predisposition (to disease); disposition; tendency
character (of a group, organization, etc.); innate characteristics; make-up; nature; culture
彼の体質は強い。
His constitution is strong.
冷えやすい体質だ。
I have a constitution that easily gets cold.
彼女はアレルギー体質だ。
She has an allergic constitution.