The sympathetic and parasympathetic nervous systems are the two branches of the autonomic nervous system, working in opposition to control involuntary functions like heart rate and digestion, with the sympathetic system driving “fight-or-flight” (action, stress response) by increasing energy use and preparing for threats, and the parasympathetic system promoting “rest-and-digest” (calm, recovery) by conserving energy and supporting daily functions. Think of them as the accelerator (sympathetic) and the brake (parasympathetic) for your body’s automatic systems.
