Regenerative collapse
From Tardis Wiki, the free Doctor Who reference
A regenerative collapse was a potentially fatal complication of regeneration. Mortally wounded by Zor, the Sixth Doctor's body attempted to regenerate when he found himself on the brink of a regenerative collapse. Fortunately, he was found and healed by Captain Jack Harkness, saving his life as well as stopping him from regenerating. (AUDIO: Piece of Mind)
