Before there was Saturday Night Fever, there was Saturday night syndrome. Eric Partridge's New Partridge Dictionary of Slang and Unconventional English (2005) gives four meanings, all originating in the United States:
1 tachycardiac fibrillationA usage example from the painter Larry Rivers' autobiography describes no. 1 as the result of "all-night dancing, carousing, and strenuous sexual activity." I remember reading somewhere, years ago, that smoking is also a factor. No. 2 results from passing out with an arm or leg hanging over a chair or the edge of a bed. The OED defines no. 2 as Saturday night palsy and Saturday night paralysis (while making no mention of Saturday night syndrome).
2 prolonged local pressure on a limb with resulting prolonged ischemia (inadequate blood supply)
3 the stress and fear suffered by preachers who wait until Saturday night to write their Sunday sermon
4 the tendency of a restaurant kitchen to fail to live up to its highest potential on the busiest night of the week, Saturday night
I foresee no Saturday night syndromes in my Saturday night, which will probably involve reading Madame Bovary while Elaine is at an orchestra rehearsal.