The Polyvagal Theory The autonomic nervous system is traditionally described as consisting of two antagonistic and balanced branches, the sympathetic and the parasympathetic system. The sympathetic system or the “fight or flight” arousal system kicks into gear when we perceive threats. When that happens your blood pressure increases, your muscles … Continue reading Immobilized by ME/CFS and/or FM? The Polyvagal Theory, the ANS and Movement Restriction