We are none of us able to avoid exposure to stress. In some cases, it can have a negative impact on our bodies, which disrupts its functions and renders it more susceptible to diseases. Stress is the body’s response to factors arising in its external or internal environment. We call these factors ‘stressors’ and they accompany us practically every day. They can, for instance, be physical or psychological stimuli, or infectious agents.
The sympathetic nervous system is known as the ‘fight-or-flight’ system because it is activated in situations which threaten homeostasis. The body then mobilises all its forces in order to survive unfavourable conditions. The intensified activity of this system is manifest in, inter alia, the excitation of the working of the heart, a rise in blood pressure and increased ventilation of the lungs. In stressful situation, the body is constantly in a state of readiness and functioning ‘in top gear’. If this state is prolonged, then those negative consequences, such as, for instance, increased vulnerability to infection or disorders of the cardiovascular system, will arise.