Your emotional state has a direct effect on your health and well being. Your body responds to stress with activation of the sympathetic nervous system. Structures within the brain serve as control panels for these functions. One of these control panels is in your hypothalamus. It overrides the parasympathetic nervous system which calms emotions. Activation of the posterior hypothalamus intiates a “flight or fight” response. This is the same “freeze” response you have when you are suddenly startled by something you did not expect. You may fall to your knees or drop a glass you are holding when someone jumps out and startles you.
When you are startled arteries thoughout your body constrict and other vessels dilate to increase the flow of blood back to your heart. Your adrenal glands release chemicals that tell your body there is a threat. If the stress continues cortisol is released. Cortisol has both short term benefits and long term negative effects. This complex response is part of a new field called psychoneuroimmunology and is part of the mind-body connection.