Anti-yukkuritis, or "un-easy sickness", is a lethal disease for yukkuris.
Yukkuris will be possible to develop anti-yukkuritis when they are fallen into deep depression, overwhelmingly stressed, or left with serious psychological trauma. The most common cause is a yukkuri that saw their entire family killed in front of their eyes.
Yukkuris who developed anti-yukkuritis will enter a mentally-dead state. They will stop all their common living actions like moving, wiggling bottoms, doing rub-rub or stretch-stretch, eating food, excreting, sleeping, mating, and others.
All they will do are expressing a mad, dull, and retarded face and crying "Easy" repeatedly.
They will no longer react to external stimulation such as greeting "Take it easy", doing rub-rub, or even beating. Tears, saliva, urine and feces will come out without control.
Unable to eat anything, the sicked yukkuris will die of starvation in a short time.
Uncontrollable loss of feces will result a condition called "Diyurrhea" which is much more lethal for koyukkuris.
Koyukkuris have very small amount of paste in their bodies and diyurrhea will result of them shitting out their paste very quickly, killing them in minutes.
In most of the works, once a yukkuri develops anti-yukkuritis, there is no way to cure her.
Examples are shown in post #36621, post #65298, post #71338, and many more.
In some works, pre-anti-yukkuritis (when a yukkuri is about to go crazy but not yet) can be prevented by an orange juice or vaccine injection (e.g. post #66896) or by them seeing/remembering something that strengthens their mind (e.g. post #69431)
An anti-yukkuritis vaccine exists to prevent anti-yukkuritis. It's mainly used for yukkuris that will be exposed to extreme stress but we don't want them to die (e.g. compost yukkuri).
The tag should be used when yukkuris develop such a disease.
Madness is similar to this tag but is different (see madness wiki page for details)