The Chemistry of Anxiety

Anxiety is an important mechanism that has ensured the survival of the human species. In the modern world, however, that same chemical response often harms instead of helping humans.
The Chemistry of Anxiety

Last update: 28 November, 2019

With the ever-increasing prevalence of anxiety, it’s more important than ever to know what it entails so you can take proper measures to prevent it. Knowing what it entails can help you and the people around you avoid catastrophic thinking and other common symptoms of anxiety. In this article, we’re going to talk about the chemistry of anxiety to explain what happens from the initial trigger to the increase of T-cells in your body.

A stressed woman with her hands on her head.

Is anxiety bad?

Many experts consider stress and anxiety one and the same. However, one tends to be more stigmatized in today’s society. They’re both related to the body’s stress response, which is a natural biological process that’s important for human survival. Consequently, you shouldn’t consider anxiety good or bad.

When a perceived threat makes people feel anxious or afraid, the activation is what often triggers the fight or flight response.

Human beings evolved with this mechanism because it has ensured our survival. Without it, you wouldn’t be able to act quickly and make crucial on-the-spot decisions. Your body wouldn’t have the physical ability to protect itself.

The problem arises when your body triggers your stress response for “threats” that aren’t dangerous. Your body then prepares for fight or flight, even though that reaction is completely unnecessary. The chemical and emotional responses involved in fight or flight are what make you feel so strange when you’re anxious.

The chemistry of anxiety

Evaluating the threat: fight or flight

When you identify a threat, you evaluate it in a matter of seconds. While people aren’t often chased by lions anymore, that reaction is equally applicable to anything that you perceive as a threat. It could be anything from a simple comment to a strange and sudden noise you consider threatening.

The sympathetic nervous system

After evaluating a threat, your body chemistry kicks into action. In the sympathetic nervous system, your hypothalamic-pituitary-adrenal axis is activated, which then triggers the release of adrenocorticotropic hormone (ACTH).

The hypothalamus regulates the release of ACTH in the body. The hypothalamus is also responsible for regulating eating, drinking, mating, and aggression. Thus, it makes sense that the neurohormonal mechanisms of the stress response are also triggered, stimulating the pituitary gland to release ACTH.

ACTH, in turn, stimulates the adrenal glands, which flood the bloodstream with glucocorticoids.

Glucocorticoids help you during stressful situations

Glucocorticoids give you the ability to survive stressful situations. That includes anything from physical injuries, such as breaking your leg or falling out of a tree, to situations that involve anxiety, fear, and hunger.

Glucocorticoids stimulate adrenaline and endogenous opioid peptides. The latter are involved in homeostasis (maintaining the body’s equilibrium), pain regulation, cardiovascular control, and stress.

The release of adrenaline and other hormones pauses some bodily functions that could be a burden in stressful situations. Digestion, for example, takes up a lot of energy. That’s why you can have an upset stomach or lose your appetite after an anxiety attack. Just be patient and let your body recover.

Your body releases opioid peptides to help you better tolerate pain from any potential injury.

The consequences of these chemical reactions

This hormonal activation causes a lot of changes in your body, and not just the ones you might expect. The stress response causes many internal changes that aren’t always evident.

In response to the hormones, your heart rate increases to facilitate blood flow and increase your oxygen levels. This is very characteristic of anxiety, and one of the things that patients often work on the most.

Some of the techniques psychologists use to reduce the stress response are controlled breathing and progressive muscle relaxation. Both techniques resort to breathing as a way to reduce anxiety. Mindful breathing can reduce your heart rate and help you calm down.

During a stress response, your spleen also contracts and releases many red blood cells. This is very useful in the case of an injury. Although many of the “threats” we perceive today don’t represent actual physical danger, remember that your ancestors ran from wild animals to protect themselves. Red blood cells are part of your immune system and they protect you in case of a possible infection.

The liver also synthesizes and releases sugar into the bloodstream, while bronchial dilation increases your breathing capacity in response to a greater demand for oxygen.

Another consequence of these chemical reactions is pupil dilation, which allows more light to enter your eyes so you can see the outline of objects better. The last thing your body does in response to a potential threat is to increase coagulation activity in the blood and increase the circulation of T-cells (a kind of white blood cell).

A woman dealing with the chemistry of anxiety.

The key to reducing anxiety

As you can see, the chemistry of anxiety has a very specific purpose. The good news is, so does the chemistry of relaxation and all of the mechanisms that activate it. In fact, the primary goal of relaxation techniques is related to the parasympathetic nervous system.

While the sympathetic nervous system activates the systems in your body, the parasympathetic nervous system decreases muscle tone and slows your breathing down. It also increases arterial dilation, which increases peripheral blood flow. The parasympathetic system decreases your breathing rate, the release of adrenaline and noradrenaline from the adrenal glands, and your basal metabolism.

The key to reducing anxiety is this fact: the sympathetic and parasympathetic nervous system can’t be active at the same time. Breathing and relaxation techniques can help you deactivate one and activate the other.

Anxiety has an evident biological and physiological foundation. In response to a threat, the body prepares itself for what might happen. On the other hand, we know that the actual threat of danger isn’t what triggers the chemistry of anxiety but the perceived threat of danger.

Anxiety isn’t bad in and of itself. The physiological mechanisms that make the stress response possible are normal and necessary. Anxiety becomes a problem when you perceive everything to be a threat, whether or not it actually is.

In that case, the body prepares itself for something that isn’t going to happen. It’s like stepping on the gas pedal when you’re in neutral – you’re using up your energy for no reason at all.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

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  • Marks, I.M. (1987). Fears, phobias and rituals. Nueva York: Oxford University Press.
  • Schulte, D. (1997). Behavioural analysis: Does it matter? Behavioural and Cognitive Psychotherapy, 25, 231-249.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.