Charak Samhita
कर्मौजोबलवर्णानां नाशो मृत्युरथापि वा । उदानेनावृते प्राणे तं शनैः शीतवारिणा ॥२०८॥
In condition of occlusion of prana by udana, there will be loss of function, vital essence, strength and complexion or it may even lead to death.
english translation
karmaujobalavarNAnAM nAzo mRtyurathApi vA । udAnenAvRte prANe taM zanaiH zItavAriNA ॥208॥
hk transliteration by Sanscript