simple wasting disease

roll a saving throw
success = you shake off the disease with little more than a headache and a sniffle
failure = you lose Constitution immediately and then again every morning until your Con reaches zero or you receive magical healing
how much Con? = roll 1d4+1, divide Constitution by that number (round up)

my Con is 18, the roll is 2 (1+1), you lose 9 Con and you'll be dead by morning
my Con is 9, the roll is 5 (4+1), you lose 2 Con now and 2 Con every morning until you're dead