What is the concept of stress

In a medical or biological context stress is a physical, mental, or emotional factor that causes bodily or mental tension. Stresses can be external (from the environment, psychological) or internal (illness, ).

In psychology, stress is a feeling of strain and pressure. Stress is a type of psychological pain. ... Humans experience stress, or perceive things as threatening, when they do not believe that their resources for coping with obstacles  are enough for what the circumstances demand.

there are 3 different types stress — acute stress, episodic acute stress, and chronic stress. The 3 types of stress each have their own characteristics, symptoms, duration, and treatment approaches.