When you don’t experience stress, cortisol still gets produced in your body, but in much smaller amounts. It follows circadian rhythm with the highest concentration in the morning, which triggers blood sugar levels increase to give us the energy to get up from the bed. Cortisol levels decrease slowly from the morning until noon, when it reaches its lowest. That’s when you feel low energy and hunger to restore this energy.
The lowest cortisol levels in the circadian circle also happen a few hours before we wake up, for a better body regeneration. But when cortisol is additionally produced in response to stress, its natural circadian rhythm gets de-regulated. It doesn’t reach its lowest levels at night making good regeneration impossible. Not only it disturbs the quality of your sleep, but it may also lead to more severe consequences, such as diabetes, muscle atrophy or metabolic syndrome.
Cortisol is produced from LDL, or so-called “bad” cholesterol. When you are in a state of chronic stress, our body needs to be alert all the time and ready to produce cortisol. It requires, therefore, more cholesterol from which this cortisol can be readily manufactured.
The primary function of cortisol in stress response is to protect basic life functions. Because medium-term energy reserves of glycogen (from glucose) get used up during the first GAS (General Adaptation Syndrome) stage by adrenaline, cortisol gets energy from fats in the body to deliver it to the most important organs – the brain and the heart. One of the processes that cortisol triggers is glucose production from the muscle protein in the body, eating your muscles. That’s when, to deliver the energy needed, you sacrifice our existing muscles which in the long run can lead to muscle atrophy.
In protecting the body’s most vital functions, cortisol also takes care of our lungs, making sure they get enough oxygen. It does so by causing sodium, and therefore water retention, which fills the blood vessels for the oxygen to flow easier. In the long term, this can lead to vessel damage and all the accompanying issues.
The resources in your body are not limitless, and when cortisol redirects them to protect the brain, heart, and lungs, it means that other organs get stripped out from their portion, causing overall organism weakening. Your immune system suffers which makes you more vulnerable to infections. You deposit more fat in the stomach area (which is considered toxic because of its correlation with heart disease, including stroke). You lose muscles even though you exercise regularly. You sleep worse, constantly feel tired and are at high risk for depression.