Parasympathetic activity

Your parasympathetic nervous system belongs to your autonomic nervous system. Put simply, it is the “automatic” nervous system that regulates involuntary bodily processes. For example, it controls things like:
Heart health (blood pressure, heart rate, etc.)
Digestion (rate of digestion, insulin release, etc.)
Waste removal (ability to urinate and defecate)
Breathing (controlling airway muscles to optimize lung function)
Sexual function (feelings of arousal)
Other bodily processes (pupil dilation, tear production, saliva production, etc.)

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The parasympathetic nervous system manages your bodily responses during rest, which is different than your sympathetic nervous system, which manages your “fight or flight” response.

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Parasympathetic activity can be an insightful health indicator. Parasympathetic activity reflects the body’s ability to recover and relax, which is crucial for cardiovascular and nervous system health. If you have parasympathetic nervous system issues, you may experience symptoms such as constipation, increased heart rate, abnormal heart rhythms, sexual dysfunction, or problems digesting food. Any of these symptoms can indicate a broader issue such as type 2 diabetes, congenital or genetic conditions, sexual dysfunction, nerve damage, or trauma. Thus, measuring parasympathetic activity is important.