1. External physical environment: including natural and human factors. Changes in the natural environment include cold, heat, humidity, strong light, lightning and air pressure. , can cause frostbite, heatstroke and other reactions. Man-made factors include air, water, food, radiation, noise and other aspects of pollution, which can lead to illness and even disability in severe cases.
2. Personal internal environment: The distinction between internal and external environment is artificial. Many problems in the internal environment often come from the external environment, such as nutritional deficiency, sensory deprivation, and * * * surplus. The imbalance between the production and balance of various essential substances in the body, such as the increase of endocrine hormones and the changes of enzymes and blood components, can be both a stress source and a part of stress response.
3. Psychosocial environment: A lot of evidence shows that psychosocial factors can cause systemic adaptation syndrome, which is manifested as stress. Psychological and social factors will cause benign pressure, such as winning prizes and promotion; It will also cause bad pressure, such as losing in the competition and losing relatives. Stress has a double effect on health. Appropriate pressure can improve the adaptability of the body, but excessive pressure will lead to dysfunction of the body when the adaptive mechanism fails.