Stress Hormones 101

Stress involves the release of hormones that can affect many aspects of your body and mind. You should know about three major stress hormones. All of them are released by the adrenal glands in response to signals from the brain (the hypothalamus) and the pituitary gland that are triggered when you are under stress.

Ideally, the stress hormones are supposed to prepare you for a real stressor that you need to fight against or flee from. This is called the “fight or flight response.” Nowadays, there are fewer real stressors and more stressor that we can’t do anything about. These stressors lead to the release of hormones that cause negative body responses because they stay constant in the body and result in bodily changes that were evolutionarily meant to be temporary.

Epinephrine

Epinephrine is released by the adrenal medulla in response to a stressor. If the stressor is a sudden thing, such as an averted car accident, you feel the effects of the epinephrine but it goes away when you realize that everything is all right. When the stressor is chronic, however, there is a problem with ongoing high levels of epinephrine that negatively affect the body.

Epinephrine has the following effects on bodily systems:

• Increased heart rate. This isn’t a dangerous thing over the short haul but it is a problem when it results in elevated heart rate over time. The heart eventually becomes stressed and has to work harder, leading to damaging effects on the heart.
• Increased muscle strength. This is also good if you are actually fighting a stressor. It is a bad thing, however, when stress is chronic, and the muscles are left tense and eventually painful. Chronic muscle tension can lead to headaches and body aches that interfere with daily living.
• Increased blood pressure. Increased blood pressure is never a good thing when it is chronic. Chronic stress can lead to chronic elevations in blood pressure so that there is stress on the heart that can ultimately lead to heart failure or heart attack.
• Shifts blood from one place to another. Under the effects of epinephrine, blood is shunted away from the core of the body and onto the muscles and brain. This allows you to move faster and be stronger during a fight situation. If you aren’t in a real fight situation, the end result is a lack of good blood supply to the digestive tract so that indigestion and gastrointestinal symptoms like cramping, constipation, or diarrhea result.

Norepinephrine

Norepinephrine is also released by the adrenal medulla under situations of increased stress. Norepinephrine works with epinephrine as part of the “fight or flight response.” It acts a little bit differently on the body than epinephrine, although they are closely chemically related.

The effects of norepinephrine on the body are as follows:

• Increases oxygen to the brain. The norepinephrine causes oxygen-bound hemoglobin to rush to the brain so that you can think clearly under times of stress.
• Increased heart rate. This is good in the short run but eventually, an increase in heart rate can stress the heart and can lead to heart failure.
• Increased blood sugar. This provides fuel for muscles in cases of a real fight or flight situation. If there is no real fight or flight situation going on, this elevation in blood sugar is unnecessary and you end up at risk for type 2 diabetes.
• Increased breath rate. This can be asymptomatic but, in those who have breathing problems already, it can result in breathing problems and chronic shortness of breath.

Cortisol

Cortisol is released from the adrenal cortex in response to stress. Cortisol has many effects on the body, including raising blood sugar and suppressing the immune system. These things are good for acute stressors but bad for chronic stress. This puts infections, like cold or flu and us at risk for diabetes (type 2). Over the long haul, it is not a good idea to have excess cortisol in the bloodstream but, unfortunately, this is the situation in chronic stress.