Stress and Adrenaline

Stressed Couple

Adrenaline is the hormone that makes your heart race, causes you to breathe fast and makes you feel anxious when you encounter stress. This hormone increases as part of a programmed stress response activated to help you manage what your body perceives as an immediate threat. If your stress is ongoing however, this response is prolonged and may convert an initial protective mechanism into negative effects on your health.

The Adrenal Response to Stress

As part of a complex, well-regulated "stress response," your body makes more adrenaline (also called epinephrine) and cortisol, the primary stress or survival hormones. When the stress or threat is gone, the hormones and their actions go back to normal levels.

Adrenaline Production

The adrenaline response to stress is transmitted through the autonomic nervous system to nerve endings and the adrenal glands. To increase adrenaline production and secretion, stress activates a complex interaction that involves:

  • Activation of the locus coeruleus, the hypothalamus and other areas in the brain that control and coordinate the adrenaline stress response
  • Activation of the sympathetic nervous system, part of the complex autonomic nervous system which includes nerve cells, nerve pathways and nerve endings in the spinal cord, brain, your adrenal glands and other organs
  • Signals to the region of adrenal glands called the medulla, which lies in the middle area of the glands, carried through the autonomic nervous system cells and pathways
  • The hormone (neurotransmitter) noradrenaline (norepinephrine) which transmits signals to the brain, the sympathetic nervous system and the adrenal glands and from which adrenaline is made
  • Other hormones such as cortisol

When stress activates this complex system it increases the enzyme that converts noradrenaline to adrenaline in the adrenal medulla and the blood level of adrenaline as well as noradrenaline (catecholamines) rise.

How you respond to stress and how much adrenaline and other hormones increase depends partly on how you cope with stress, your life experiences and your genetics.


At the same time, stress activates the hypothalamic-pituitary-adrenal axis (HPA) to increase production and cortisol from the outer region of the adrenal gland called the cortex. Cortisol is also essential to the increase in the enzyme that converts noradrenaline to adrenaline.

The Role of Adrenaline in Stress

Adrenaline is part of the so-called "fight-flight" response to stress that protects you from harm. Adrenaline normally helps to maintain your body's basic functions (homeostasis) and affects every organ in the body. Increased production and release of adrenaline in response to acute stress enhances its protective functions but may also be detrimental to those at risk.

In response to acute stress, increased adrenaline mostly speeds things up and leads to:

  • Heightened awareness and alertness to deal with the stressful situation
  • Increased energy to fight or run
  • Increased heart rate and force of contraction of the heart, which in a person with heart disease could trigger a heart attack
  • Increase blood pressure which could also trigger a stroke or heart attack in a susceptible person
  • Increased breathing to provide more oxygen to your tissues
  • Mobilizes glycogen (starch) from your liver to convert it to glucose for energy
  • Increased perspiration
  • Decreased response to pain
  • Decrease in bowel function

Cortisol plays its own role in protecting you, including providing fuel for your muscles and brain. These responses all arm you to survive episodes of stress or any other threat to your body.

Adaptation Response

Adrenaline and cortisol and other parts of the stress response also play a beneficial role in helping a person adapt and manage stressful episodes. However, when the response is not turned off, or when it is repeatedly triggered, then the adaptive (coping) mechanism is overloaded and may not be effective.

Effect of Sustained Stress

Under sustained stress, your adrenaline and other stress hormones stay elevated and you might feel that you are constantly under siege. The initially protective adrenal response to stress can become detrimental to your health and your feeling of well-being by its continued presence.

Too much and prolonged adrenaline and stress can lead to physical, behavioral and psychological disorders including:

  • Heart disease such as an enlarged heart, heart failure and irregular heartbeat
  • High blood pressure
  • Stroke from high blood pressure
  • Irritable bowel
  • Eating disorders from disturbed bowel function
  • Weakened immune system
  • Autoimmune diseases
  • Headaches
  • Anxiety, irritability, shakiness
  • Depression
  • Sleep disturbance
  • Lack of motivation and drive secondary to anxiety and depression
  • Skin disorders such as psoriasis and other skin rashes
  • Memory and learning impairment
  • Accelerated aging

Managing Chronic Stress

The after-effects of acute stress or multiple, daily, chronic or repeated stresses, including accompanying sleep deprivation, can rob you of your sense of well-being and make you sick. Strategies to manage your stress to decrease your risks for stress-related disorders can include:

  • Change or control what you can which might include a change of jobs
  • Get enough sleep and eat a healthy diet
  • Exercise, which increases endorphins in your brain
  • Learn and practice relaxation techniques which can trigger the "relaxation response" and diminish the responses to stress such rapid heart rate, high blood pressure and anxiety
  • Build a support network of people you can trust and rely on
  • Engage in activities or learn a new skill that bring you joy

In addition, don't hesitate to seek help from a trained psychotherapist who can help you better understand your sources of stress and how to better cope with them and improve your well-being.

Stress and Adrenaline