I know when some of my alters are out they hold their breath. Others stiffen their muscles. Me, Deb51, feels sore or dizzy after they come out. And if somebody comes out really strong so I am way in the back and then someone else comes out really strong and then I have to come back in a hurry like at the end of therapy sometimes or if the situation changes and they don't know how to deal I can get really icky headaches...thank goodness they don't last long.