I just learned this one this morning while reading Puzzling out SIADH in the November/December 2013 issue of Nursing Made Incredibly Easy!
To remember the early signs of syndrome of inappropriate antidiuretic hormone (SIADH), think FLAT:
Here are more nursing tips, and some other mnemonics and "memory joggers" that you might find useful.
Pullen, R. (2013). Puzzling out SIADH. Nursing Made Incredibly Easy!, 11(6)