Tired - This condition marks that a character is performing below average.
A character becomes tired after Full Moon Operations or by participating in too many battles inside Tartarus. The Protagonist can become tired himself if he draws the "very worst luck" fortune in the shrine. While Tired, a character is more likely to miss, takes more damage, has trouble recovering when knocked down, and will leave the party if taken to the first floor.
Sick - A Sick character takes longer time to recover from being knocked down, will be more susceptible to status changes, and the protagonist cannot study at night. Also all stats, attacks, and spells effects are lowered significantly. He can still visit Mr. Edogawa during the day. This status changes to Good if the character sleeps early. Characters other than the protagonist will return to good after roughly a week of not visiting Tartarus. Sick characters can still go to Tartarus in Sick condition, but they will get tired fast.