Many functions in the body are under voluntary control. These functions include moving your arms or legs, walking, chewing, and talking. However, some functions (like your heart rate, blood pressure, body temperature, pupil size, and digestive functions) are not under voluntary control. These functions are considered autonomic.
The autonomic nervous system (ANS) is very important in controlling many functions in your body. The ANS is composed of two parts, the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS)
If you were to be frightened by a loud noise or a threatening situation, then your sympathetic nervous system (SNS) would be activated. Your heart rate would increase, your blood pressure would rise, your pupils would enlarge, your airways would expand, the mucus production in your nose, throat, lungs and bowels would cease, your blood sugar would rise, your immune system would stop working.
These effects all occur almost instantly when we are faced with a threatening situation. Your body has been programmed through evolution to survive these situations by activating this SNS.
The SNS is like the “gas pedal” in your body. Where there is a gas pedal, there better be a brake, otherwise these functions would continue and the body would suffer harm. The parasympathetic nervous system (PNS) is like the “brake” in your body.
When the PNS is activated, your heart rate would decrease, your blood pressure would drop, your pupils would constrict, your airways would contract, the mucus production in your nose, throat, lungs and bowels would increase, your blood sugar would drop, and your immune system would be activated.
Some people have very sensitive autonomic nervous systems and can over react to external and internal stimuli. This situation is called Autonomic dysfunction.
Autonomic dysfunction (an over or under active system) can therefore lead to many different symptoms.
For example, an overactive SNS (or under active PNS) can contribute to high blood pressure, palpitations, anxiety, constipation, ulcers, insomnia, high blood sugars, dry mouth, immune system problems and erectile dysfunction.
An overactive PNS (or under active SNS) can contribute to low blood pressure, fatigue, depression, diarrhea, ulcers, low blood sugars, anxiety, allergic reactions, asthma, sinus problems and watery eyes and nose.
The SNS and the PNS can be stimulated by various foods, supplements and emotional experiences. The ratio of calcium to potassium is very important to SNS and PNS activity (a high calcium/potassium ratio activates the SNS and a low calcium/potassium ratio activates the PNS) A high blood sugar can stimulate the PNS, a low blood sugar the SNS. There are many other specific minerals, amino acids and vitamins that can affect autonomic balance.
The autonomic nervous system is one of several homeostatic control mechanisms in the body. Homeostatic control mechanisms maintain stable internal conditions to compensate for changing external conditions. When your body is unable to adequately compensate for changing external conditions, numerous symptoms can result.