When your body gets stressed, such as in times of emotional distress, exercise, surgery, illness, or even daily living, hormones are produced by the adrenal glands called Glucocorticoids. One of them, Cortisol, should be highest first thing in the morning, to combat the stress of overnight fasting and to get the body ready for the day's activities. It should gradually decline throughout the day, being lowest at bedtime and through the early night. Its gradual rise in the early pre-dawn hours is what naturally wakes you up in the morning.
Cortisol plays an essential role in immune function. It mobilizes the body's defenses against viral or bacterial infection and fights inflammation. However, over long periods of time, high cortisol levels can actually suppress the action of the immune system and make you more likely to get frequent infections.
Cortisol also maintains adequate blood levels of glucose. The brain gets most of its energy from glucose, so this is an important task. After a period of not eating, the body's cortisol production increases. This increase initiates catabolism or the breakdown of protein into simple amino acids and their conversion into glucose to feed the brain.
So What Happens When You're Stressed All the Time?
Chronic, excessive stress (emotional or physical) can cause the adrenal glands to become exhausted so they can no longer produce adequate cortisol.
Low cortisol levels lead to low blood glucose (hypoglycemia), excessive fatigue, and increased susceptibility to infection. See
Adrenal Dysfunction for more information.
Constant emotional, physical or mental stress, excessive intake of alcohol (more than one glass of wine per day), and even minor amounts of sugars and refined carbohydrates can lead to insulin resistance, which in turn can increase levels of cortisol. This can create symptoms of high blood pressure, joint pain throughout the body, insomnia, restless legs, aging rapidly, loss of muscle tone, and weight gain through the middle of the body. Eventually, if very high Cortisol levels are untreated, it can lead to cardiac stress.
