nervous system is faster than the HPA axis. When stress occurs, the hypothalamus secretes CRF, which is corticotropin-releasing factor, which causes the pituitary gland to release ACTH, which is adrenocorticotropic hormone. This leads to the adrenal release of cortisol, which helps initially but later weakens the immune system. These stress responses will be favorable in the beginning but will ultimately have negative consequences if the stress is prolonged. High cortisol levels can weaken the immune system, lead to depression, and increase the risk of infectious diseases. People with extreme stress can have major depressive disorder and PTSD. There is an increased risk of heart disease, musculoskeletal diseases, endocrine disorders, metabolic disorders, and nervous system diseases.
STRESSORS There are different things that qualify as stressors. Stressors can be chronic and extend over a prolonged period of time; they can also be acute but will have effects that last for a period of time, such as an acute injury that has long-term consequences. Stressors can be major or can be minor but persistent, such as dealing with traffic. Traumatic events are usually major stressors, such as those that threaten life or serious injury. It can be a single event or multiple life-threatening events that occur over a period of time. Traumatic events tend to happen more to men, non-white individuals, and people of a lower socioeconomic status. Traumatic events will lead to PTSD or posttraumatic stress disorder. Significant life changes can be stressful, such as moving, divorce, marriage, or death of a loved one. There is a definite link between life changes and significant illness, even if the life changes are positive ones. Holmes and Rahe developed the Social Readjustment Rating Scale or SRRS, which looks at 43 different life events that result in the greatest need for personal readjustment. Positive and negative changes are described and these tend to be cumulative over time. There are certain life-change units, called LCUs. The highest LCU happens with the death of a spouse, with divorce being the second highest life change. The scale ranks the LCUs a person has experienced over the prior 12 months.
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