Stress Effects Cortisol

Stress hormones and the cortisol released during periods of stress can have serious health consequences over time. Discover the connection between cortisol and stress, and how cortisol can affect your weight and health.

The Importance of Stress

Stress is the physical expression of our fight or flight survival mechanism. A threatening or tense situation triggers a stress response, which prepares us to confront or flee. In this sense, stress hormones and cortisol released during a period of stress can give your body the advantage you need to survive a dangerous situation.

Unfortunately, the stress response may also occur when no physical danger is present. For example, the demands of an unreasonable boss or being stuck in traffic day after day can trigger stress hormones and cortisol may begin to take a toll on your body. Stress is generally considered to be acute or chronic. Acute stress prepares us for fight or flight, and is generally short-term. Chronic stress lasts longer, and is the main cause of stress-related health problems.

The Stress Response

During the fight or flight response, the hypothalamus triggers the combination of nerve and hormonal signals. This signals the release of more than 17 different hormones–including cortisol–causing these physical changes:

  • Blood diverted from nonessential areas, including digestion and kidneys
  • Elevated blood pressure
  • Elevated blood sugar
  • Faster breathing
  • Increased heart rate.

Stress Hormones: Cortisol

During stress, the adrenal glands produce and release cortisol. In a short-term emergency, cortisol helps speed tissue repair. During chronic stress, however, elevated cortisol levels compromise health in a number of ways, including causing fat stores. The fat circulating in your body is relocated and deposited around the abdomen, causing weight gain and obesity.

Cortisol is one of the hormones associated with waking and sleeping. Levels of cortisol naturally fluctuate during the day, but they are highest in the morning and lowest at night. Higher levels of cortisol in the morning help us wake up. When chronic stress stimulates cortisol production, the daily cycle is disrupted. For example, high levels of cortisol at night can result in insomnia.

Although cortisol has anti-inflammatory effects in the short run, it can actually cause inflammation during long periods of stress. The immune system becomes compromised as cortisol causes immune cells–particularly natural killer (NK) cells–to shut off and stop working, disappearing from the blood. These cells can even become destructive to body tissues and cause allergies and autoimmune diseases.

Other health problems associated with elevated stress and cortisol levels include:

  • Depression
  • Digestive problems
  • Heart disease
  • Memory loss.


Benjamin Associates. (2007). Stress and the immune system. Retrieved October 1, 2010, from

Del Gatto, S. (2007). Identifying different types of stress. Retrieved October 1, 2010, from

Maglione-Garves, C. A., Kravitz, L.