Sympathetic Nervous System Symptoms of Stress

Under normal conditions, the sympathetic nervous system works in concert with the parasympathetic nervous system to manage the internal affairs of your body. As part of its housekeeping chores, it regulates your blood pressure by controlling your heart rate and the contractions of your blood vessels. In stressful situations, it plays a major role in creating the physiological arousal involved in mobilizing your physical resources.

In normal times, the SNS exerts its effects on the body by secreting small amounts of a neurotransmitter substance called noradrenaline directly onto the organs it is stimulating. However, in times of stress, the SNS calls upon the adrenal gland to secrete additional noradrenaline into the blood stream along with a more powerful neurotransmitter substance, adrenaline. Unlike the small amounts of noradrenaline secreted by the SNS, adrenal secretions affect the whole body, not just a single organ. They're bigger, more potent, more general, and longer lasting.

These neurotransmitters circulating in your bloodstream provide a double dose of noradrenaline, accompanied by the extra "kick" of adrenaline. The physiological arousal created by SNS stimulation directly to a particular organ is rather short lived. But the arousal created by adrenaline circulating through your entire bloodstream can persist for hours. When your adrenal gland gets involved in your physiological reactions, your stress reaction, to paraphrase Yogi Berra, ain't over when the stress is over. Hormones also play a part in your chemical recipe for panic.

Hormones (particularly cortisol from the outer shell of the adrenal gland) increase organ sensitivity to adrenaline and noradrenaline. This, too, raises your level of physiological arousal. For instance, adreno-cortico-trophic hormone (ACTH) is released by your pituitary gland into your bloodstream, where it travels to your adrenal gland. Once there, it stimulates the cells forming the outer layers of the adrenal gland, the adrenal cortex, to release a number of astressae hormones, including cortisol, into your blood stream.

One of cortisol's many functions is to increase the sensitivity of organs such as your heart and blood vessels to the stimulating effects of noradrenaline and adrenaline. Your cardiovascular system becomes sensitized. When you experience acute, episodic stress, your cortisol-sensitized heart and blood vessels require less and less noradrenaline and adrenaline to climb to higher and higher levels of activity and then stay there for longer and longer periods of time. This is one reason that people who suffer one panic attack are likely to have repeated panicky feelings in the following weeks.

If your levels of arousal climb into the danger zone only occasionally, you're more likely to develop symptoms involving your muscular system and your PNS. If it reaches the danger zone in the repeated bursts of arousal found in acute, episodic stress, however, you may also develop symptoms involving your SNS, such as panic attacks or cardiovascular symptoms of rapid heart beat or migraine headaches. Your particular pattern of symptoms also depends on your genetic makeup, any previous illness or injury, and your general history.

Click on other stress symptoms you may have experienced to learn more about what you can do about them as well.