Term originally coined by Dr. Dan Siegel, to describe the optimal zone of arousal in which a person is able to function most effectively.
When you are in this zone you are able to effectively able to take in and process information and respond to the demands of everyday life without too much difficulty. When we are outside this zone it is difficult to take in information, think rationally and healthy make decisions.
When a person is experiencing hyper-arousal, they are in a state of fight or flight. Their system is revved up and they may be experiencing anxiety/panic or anger, racing thoughts, and hypervigilance.
When a person is experiencing hypo-arousal, they are in a state of freeze. Their nervous system is in shut down and they may be experiencing emotional numbing, mind going blank, dissociation, or paralysis.
When there has been chronic traumatic experiences and stress our window of tolerance shrinks, so that it take less to throw us into hypo or hyper-arousal.
Therapy, self-care, mindfulness practices and yoga can all help widen the window of tolerance so that you can handle more without overwhelming your system.