When a person is under stress, the body reacts to stimulation of the sympathetic nervous system. This phenomenon is called the โfight or flight responseโ, as the body arms itself against what it perceives as a threat. When this happens, the adrenal medulla secretes epinephrine, and the hypothalamic-pituitary is stimulated to release ACTH, which in turn hormone stimulates the adrenal cortex into increasing the production of the hormone cortisol anti-stress.
When a person is under chronic stress, cortisol levels can rise so high that its production decreases as the adrenals are exhausted. At the same time, the level of DHEA, a hormone produced by the adrenal gland, also starts to drop without reaching the summit. In the case of chronic stress, there is a deficiency of DHEA with simultaneously increases cortisol levels. As a result, the ratio of cortisol to DHEA increases.
In the case of most systems, the observed hormonal negative feedback limits the production of each hormone. So it is in the case of cortisol, but with one exception. During prolonged or acute stress, when the body perceives a threat to its life, excess cortisol blunts the negative feedback. In other words, instead of cortisol production cut when it is already high, the body responds inversely. As the anti-cortisol is a stress hormone, the body interprets very high cortisol levels and impending danger, when this happens high cortisol suppresses feedback. Therefore, it produces more cortisol.
When the body is under stress, cortisol levels increased when in an environment where the feedback is suppressed. At this time, the level of DHEA decreases. The result is a high ratio of cortisol to DHEA and:
1)Reduced insulin sensitivity, weak glucose utilization and increased blood sugar, which leads to diabetes.
2)Less immunoglobulin A (major factor in cellular defense), cells NK and T lymphocytes lead to greater susceptibility to infection such as herpes, yeast, and viral infections.
3)The increased losses in bone mass since the absorption of calcium is blocked and there is osteomalacia which leads to osteoporosis.
4)Increased accumulation of fat in the waist and distribution of protein, leading to the inability to regenerate muscles and excessive weight loss.
5)Increased retention of water and salt leading to hypertension.
6)The dominance of estrogen, leading to PMSu, uterine fibroids, and breast cancer.
Note that these subsections only apply to the stage when adrenal glands arenโt exhausted yet!
