Hans Selye studied bodily reactions to the stress and presented a theory about it. According to Selye our body reacts in three ways against stress. They are described as follow : Alarm reaction stage : In this stage, the nervous system of the body becomes active to cope up with stress. For example when a person encounters a wild animal, he will try to protect himself from the animal. In such situation, the secretion of adrenal gland increases and there is release in hormones like epinephrine and non-epinephrine which provide extra energy to fight the stressful situation. As a result, the individual experiences muscular and joint ache, fever, fatigue, rise in blood sugar and blood pressure etc. In such situation, the person will fight the stressor or run away from the situation. This is how majority of people react while experiencing stress.
Resistance stage : In this stage, the body becomes active to deal with the stressor and achieve suitable adaptability. In this stage, the bodily changes are constant. But the body becomes weak to cope up with the stressors. For example : A person suffering from cancer is trying to fight against disease but while doing so he becomes victim of depression and frustration.
Exhaustion stage : In this stage, the person feels exhausted. He remains worried and collapses mentally as well as physically. Constant stress reduces the physical ability of the person. As a result the person becomes victim of diseases. The person may develop headache, high blood pressure, digestive problems and mental diseases.