Kenneth G. Wilson (1923). The Columbia Guide to Standard American English. 1993.
condition (n.)
is an accurate nonspecific word for use in medical discussions wherein specific information is unavailable (Hes got a heart condition), and in such uses it is Standard. Shes in an interesting condition, however, is a euphemism for Shes pregnant; today it sounds whimsical or faintly Victorian in tone. See also PRECONDITION.