what is the difference between sympathetic and parasympathetic nervous system?

The sympathetic nervous system is engaged when the body is under stress and the flight or flight system is activated. All of the organs that would be needed to engage in a fight or to run away are working to that capacity. The parasympathetic nervous system works to keep the body working on its daily activity level and also works to return the body to baseline after it has been under stress.

Sympathetic nervous system triggers fight or flight response, while the parasympathetic calms you down with the rest and digest response. Think of a PARAchute. It slows you down.

Both are in the business of keeping you alive. Sympathetic nervous system is crisis central. It’s going full strength when your life is threatened (escape from a predator or attacker). Parasympathetic is long-term processes that contribute to wellness and health: immune function, rest, digestion, healing.

A problem for modern humans is that these two systems can’t function well at the same time. If you are constantly stressed (which many of us are) you won’t get the benefit of parasympathetic processes. Therefore, good stress management is important for good health.

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