Stress And Cortisol
Levels, Part 1
The Better Life Experts |
February 10, 2009
Stress and Cortisol levels
Cortisol is a hormone made by the adrenal glands. It is synthesized
from cholesterol and the cortisol levels in our bloodstream rise when the
pituitary gland releases another hormone called adrenocorticotropic hormone
(ACTH).
Cortisol has many functions. It helps the body use sugar (glucose) and fat
for energy (metabolism), and it helps the body manage stress. Cortisol
levels can be affected by many conditions, such as physical or emotional
stress, strenuous activity, infection, or injury. Normally, cortisol levels
are highest in the early morning and drop to their lowest in the evening and
during the early phase of sleep. High cortisol levels
- A high level of cortisol in the blood can indicate the presence of
Cushing's syndrome, a disorder that can be caused by overactive adrenal
glands, a pituitary or adrenal gland tumor, some types of cancer, or
long-term use of corticosteroids.
- A high blood cortisol level can be caused by severe liver or kidney
disease, depression, hyperthyroidism, or obesity.
- Pregnancy or birth control pills can also cause a high blood
cortisol level.
- Conditions such as recent surgery, illness, injury, or whole-body
infection (sepsis) can also cause high cortisol levels.
Low cortisol levels
- A low level of cortisol in the blood can be indicative of Addison's
disease, which is caused by damage to the adrenal glands. If the
pituitary gland is not working well, it can cause low levels of the
hormone ACTH, which in turn causes low levels of cortisol. Conditions
that can damage the adrenal glands or pituitary gland include some
infections, head injury, and some autoimmune diseases.
- A low level of cortisol can also be caused by internal bleeding that
leads to shock.
Although stress isn’t the only reason that cortisol is secreted into the
bloodstream, it has been termed “the stress hormone” because it’s
secreted in higher levels during the body’s ‘fight or flight’ response to
stress, and is responsible for several stress-related changes in the body.
If we had to run from a predator, for example, our healthy adrenal glands
respond by releasing adrenaline, which makes us
more alert and focused, and cortisol, which
converts protein to energy and releases our stored sugar, glycogen, so our
bodies have the fuel needed to respond quickly. Stress-related changes can
be essential to our survival under certain conditions.
Some positive effects of even small increases of
cortisol
- A quick burst of energy for survival reasons
- Heightened memory functions
- A burst of increased immunity
- Lower sensitivity to pain
- Helps maintain homeostasis in the body
While cortisol is an important and helpful part of the body’s response to
stress, it’s also important that the body’s relaxation response be activated
so the body’s functions can return to normal following a stressful event.
When the threat is gone, the body returns to normal — quickly with respect
to adrenaline levels, less quickly with respect to cortisol. Unfortunately,
in our current high-stress culture, the body’s stress response is activated
so often that the body doesn’t always have a chance to return to normal,
resulting in a state of chronically high levels of cortisol and an ongoing
state of stress.
Some negative effects of prolonged, high levels of
cortisol
Higher and more prolonged levels of cortisol in the bloodstream (like those
associated with chronic stress) have been shown to have negative effects,
such as:
- Suppressed thyroid function
- Blood sugar imbalances such as hyperglycemia
- Decreased bone density
- Decrease in muscle tissue
- Higher blood pressure
- Lowered immunity and inflammatory responses in the body, slowed
wound healing, and other health consequences
- Increased abdominal fat, which is associated with a greater amount
of health problems than fat deposited in other areas of the body. Some
of the health problems associated with increased stomach fat include
heart attacks, strokes, the development of higher levels of “bad”
cholesterol (LDL) and lower levels of “good” cholesterol (HDL), which
can lead to other health problems!
- Studies done by Dr. Robert M. Sapolsky, Professor of Neurology and
Neurological Sciences at Stanford University, showed that lots of stress
or exposure to cortisol accelerates the degeneration of the aging
hippocampus. And, because the hippocampus is part of the feedback
mechanism that signals when to stop cortisol production, a damaged
hippocampus causes cortisol levels to get out of control – further
compromising memory and cognitive function. The cycle of degeneration
then continues.
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