SNS(Sympathetic Nervous system) Dominant Type - Due to hypersensitive SNS
Insomnia is typically caused by hyperactivity of Sympathetic Nervous system(SNS). SNS hyperactivity occurs in two situations. First, there is an exaggeration of the sympathetic nerve itself due to external stimuli such as stress. Second, the function of the parasympathetic nervous system(PSNS) that suppresses the sympathetic nervous system, is declined, and the SNS is relatively hyperactive. Sympathetic hyperactivity is easy to understand when we imagine confronting a bear in the woods. To fight or flight, we require a large amount of blood supply to the muscle tissues, and our heart rate goes up to pump more blood. Increased blood flow to the muscle tissues naturally reduces blood supply to the gastrointestinal system, because digesting food matters very little when we are in a life or death situation. Immediate judgment continues to be asked where to run. There is be no time for sleep. In real life, when the SNS is triggered by stress for a prolonged time, there will be confusion within the body in adjusting to daily situations properly. Thus, digestive issues arise such as palpitation, loss of appetite, heartburn, bloating and acid reflux altogether with sleep problem from being very alert to changes to surroundings.