medical condition
The "ultimate" bu**s**t excuse for unfairly getting out of an obligation/responsibility that the rest of us "normal" people have to practice/endure in everyday life.
Some people think that all they have to do is say that they have a "medical condition" or "allergy", and that this instantly/indisputably obligates everyone around them to allow for any and all unacceptable/disgusting/obnoxious/selfish behavior, or exempts them from performing certain common-courtesy actions the way the rest of the populous is expected to do! What a farce --- it allows perfectly-capable people to grossly misbehave socially, while at the same time causing those of us who do indeed legitimately suffer from certain debilitating illnesses/infirmities to be looked down upon and shown less tolerance/acceptance than we should receive, since others are already seething with resentful aggravation at all of the fakes out there to whom they are already being forced to needlessly kowtow.
unspecified medical condition
A phrase you can use to get out of a jail sentence, note that you must be Paris Hilton rich for this to be effective.
Paris Hilton: I got to party at home in my mansion while I served my jail sentence because I had an unspecified medical condition; that's hot!