We get quite a few questions about cortisol so it's time to review a few basics. In this basics series my goal is to sift through the complexity and give you information in a few minutes that you will be able to use to better manage your own health.
This is part 1 of a two part series. Part 1 is a general description. In part 2 we will talk about more practical steps of diagnosis and treatment.
Cortisol is an adrenal hormone. Hormones are biochemicals that are made in one place in the body and are carried to another target tissue where they stimulate a response. The adrenal glands are so named because they sit on top of the kidneys or as known in Latin, renal glands. The adrenals are physiologically divided into two parts, the adrenal cortex or outside layers and the adrenal medulla or inside layers.
The hormones produced by the medulla or inner layers are epinephrine and norepinephrine. These two hormones are made from the amino acid tyrosine in the adrenal glands. Interestingly enough the brain also makes epinephrine and norepinephrine from tyrosine but the neurons use these as neurotransmitters.
Cortisol gets its name from being made in the cortex of the adrenal glands. Cortisol is a key component of the body to help regulate glucose metabolism, blood pressure, insulin release for blood sugar control, immune function, inflammatory response.
Cortisol levels help the body deal with the demands of the day. Ideally the levels start out high in the morning and decrease steadily throughout the day until reaching their lowest levels at bedtime. Probably one of the reasons that working odd hours can jeopardize health is because the cortisol levels are just not right for the situation.
The adrenal gland hormones help the body deal with increased stress. If you have a temporary stress increase you might experience positive effects such as: A quick burst of energy for increased survival, improved memory functions, increased immunity and a lower sensitivity to pain. We can all agree these are good things.
The problem is that chronic stress causes a chronic increase in cortisol levels, at least until the ability of the adrenals to respond begins to fatigue. This chronic increase in cortisol causes quite a different response that is you can expect: impaired cognitive performance (brain fog), suppressed thyroid function, swings in blood levels that some will experience as low blood sugar (hypoglycemia) and some high blood sugar (hyperglycemia) that can lead to diabetes, decreased bone density, decrease in muscle tissue, increased probability of high blood pressure, lowered immunity and inflammatory responses in the body, slowed wound healing and increased abdominal fat.
Increased abdominal fat increases the probability of health problems more than fat deposited in other areas of the body. Some of the health problems associated with increased stomach fat are heart attacks, strokes, the development of metabolic syndrome, that is problems with managing blood sugar, higher levels of "bad" cholesterol (LDL) and lower levels of "good" cholesterol (HDL), which accelerates the problems further.
In Part 2 we will talk more about what can go wrong, how we diagnose the problem and what can be done about it.