What are the Root Causes of Anxiety?

March 1, 2024

There’s almost a 35% rise in mental health disorders in India. Even if we did not have a statistic, just observing the world around us is enough to come to this conclusion. While the reasons for the rise are multifold, what can be done to help those that we can? 

People often think that therapy is enough; but, in an anxiety disorder the neurobiology of your body is altered. If we can understand what exactly is changing inside us on a cellular level, we can come up with the best treatments using nutrients and supplements along with other therapeutic interventions. In this article, we will dig deep into the several root causes of anxiety disorders. 

What is Anxiety and Anxiety Disorder?

Anxiety is your body’s defence mechanism. When you are in danger, your body reacts by making you anxious and preparing itself for fight or flight mode. However, what it does not understand is the difference between a mortal, physical danger versus stress. Your mind will still react to a stressful situation (for example, talking in front of a crowd) in a similar way to that of you being in physical danger (for example, being chased by a dog). One can experience increased heart rate, rapid breathing, sweating, etc.

Nevertheless, these reactions are normal under anxiety-causing situations. Actually, these reactions are expected. You are said to have an anxiety disorder when the anxious reaction you have towards a situation becomes overwhelming, persists for too long, appears for apparently no reason, occurs frequently and interferes with your daily life.

What causes Anxiety Disorders?

There are a lot of different types of anxiety disorders such as GAD (Generalised Anxiety Disorder), panic disorder, social anxiety, phobias, OCD (Obsessive Compulsive Disorder) and more. You can suffer from one or more anxiety disorders at the same time. 

While the causes of anxiety disorders are multifaceted, the neurobiological underpinnings play a crucial role in understanding and treating these conditions. 

  1. Imbalances in Brain 

To understand anxiety, studies were conducted to see what goes on in the brain when a person is anxious. These studies revealed that the brain’s limbic system, that comprises the hippocampus, amygdala, hypothalamus and thalamus plays a major role when processing anxiety. 

A number of neuroimaging studies that were conducted showed that the amygdala, especially, brightened up every time a subject was shown pictures that induced anxiety in them. The amygdala is responsible for alerting the rest of the brain about a danger or fear and triggering a response.

It is seen that in some subjects (people who experience stressful situations higher than others like a child living in a violent home or soldiers) certain parts of their brain become more dominant resulting in the brain switching into survival more often than logical mode. It can also mean that the brains of these subjects respond to minutely stressful situations similar to dangerous situations. 

Additionally, the frontal lobe, or the ‘thinking brain’ would subsequently shut down temporarily. This occurs because during danger it is not as critical to make theoretical decisions as it is to run away from danger. 

In simple words, anxiety disorders are a result of imbalance in the part of the brain responsible for your emotions and not the cognitive centres. 

  1. Neurotransmitters

Neurotransmitters are chemicals that facilitate communication between neurons. When your sensory organs detect a stressful event like a spider crawling on the floor, the neurotransmitter secretes a chemical that tells the amygdala that a fearful event has occurred and gives the appropriate response to that situation. But, if you have anxiety disorders, you may have an imbalance of these neurotransmitters. 

A decrease in inhibitory transmitter GABA (Gamma-amino-butyric-acid) has long been linked to the presence of anxiety disorders. Other neurotransmitters that play a role in inducing anxiety disorders include serotonin, corticotropin-releasing hormone, endocannabinoids, neuropeptide Y, oxytocin, opioid peptides and dopamine. For example, low levels of serotonin are also linked to heightened anxiety symptoms.

There are several reasons why your neurotransmitters may be imbalanced such as genetic factors, digestive issues, prolonged stress and faulty metabolism. Toxins like heavy metals, pesticides, prescription drugs and drug use can also cause damage to the nerves that make neurotransmitters. 

  1. HPA Axis 

The hypothalamic-pituitary-adrenal axis or the HPA axis is a network of endocrine organs, hormones, and other signalling molecules that serves as the body’s stress-response system. One of the roles of this axis is to provide our body with cortisol - the stress hormone. If the axis keeps getting messages of danger it will keep secreting cortisol that can ultimately lead to overproduction of cortisol. This imbalance creates a lot of issues. 

It may also follow that over time your body finds itself in a position where it is unable to produce the required amount of cortisol and other hormones required to regulate anxiety. Studies show that people suffering from anxiety disorders can show an increase in cortisol levels, which can be attributed to HPA dysfunction

Some causes of HPA dysfunction include mental, physical, and biochemical stress. Inadequate sleep, inflammation, poor nutrition and exposure to environmental toxins such as mold and endocrine-disrupting plastics can also negatively influence the HPA axis. 

  1. Genetic Factors

Research indicates anxiety disorder (specifically GAD) has almost 30% of chances to be inherited by your offspring. Specific genetic variations may predispose individuals to heightened anxiety sensitivity. Identifying these genetic markers can offer valuable insights into targeted treatments.

  1. Nutrient Deficiencies   

Nutrient deficiencies are paramount with our new-age diet. Several studies show evidence that people suffering from anxiety disorders often have nutrient deficiencies. Our body uses several minerals like zinc and magnesium to produce neurotransmitters like dopamine and serotonin which play an important role in regulating anxiety. 

Even antioxidants like Vitamin A, C, E, etc act as anti-inflammatories — inflammation as we know is another reason for anxiety. Omega-3s are also crucial to maintain brain health.  There are multiple nutrient deficiencies that can be exacerbating your anxiety.

  1. Other Health Dysfunctions

A lot of ailments disrupt your body’s functioning which can lead to further disorders. One such relation is between hypothyroidism and anxiety. It is well known that hypothyroidism can cause depression, there are  also studies which show that people who have hypothyroidism have more chances of having anxiety

Additionally, our gut and brain have an open two way communication through what is called the gut-brain axis. Any problems in the gut (our gut is the primary producer of the neurotransmitter serotonin) will directly affect your brain. Thus, people with gut issues like IBS are more likely to have anxiety

Another such connection is between anaemia and anxiety. Anaemia is a disorder where a person’s red blood cell count is low or the blood is unable to transport enough oxygen. Your brain needs ample oxygen to function. Thus, people with anaemia are more susceptible to mental health issues like anxiety. 

  1. Environment and Lifestyle Factors

Apart from nutrient deficiencies, your lifestyle also dictates whether or not you are more susceptible to anxiety disorders. These include physical inactivity, stress, inflammation and trauma.  Environmental factors, such as early-life stress, have shown clear association with anxiety disorders through impact gene expression, inflammatory changes and dysregulation of the HPA axis. 

When it comes to physical exercise, in one study, researchers found those who engaged in regular intense workouts were 25 percent less likely to develop depression or an anxiety disorder over the next five years. This could be because during exercise the body releases endorphins and  chemicals in the brain that act as natural painkillers and help to reduce stress.  

Lastly, sleep deprivation can also induce or worsen anxiety. At the same time, researchers have found that people who are prone to anxiety are more sensitive to the effects of lack of sleep on mood and emotional health. 

The neurobiology of anxiety disorders encompasses a complex web of factors that contribute to the development and manifestation of these conditions. Functional Nutrition understands the neurobiology of anxiety disorders and takes into account the various factors that can lead to you being affected with anxiety disorders. If you have been unsuccessfully dealing with your anxiety disorder, it is time for you to consult a functional nutritionist and identify what are the underlying causes of your disorder rather than just treating the symptoms. 


  1. Nawab, N. (2022, October 7). Mental health care analysis. Times of India Blog. https://timesofindia.indiatimes.com/blogs/voices/mental-health-care-analysis/ 
  2. Northwestern Medicine Staff & Northwestern Medicine. (2020, June 8). The Science of Anxiety (Infographic). Northwestern Medicine. https://www.nm.org/healthbeat/healthy-tips/emotional-health/the-science-of-anxiety  
  3. Anxiety and brain. (2017, January 20). Direct. https://directindia.org/resources/anxiety-and-the-brain/  
  4. Your brain when you’re anxious. (2023, August 3). Kids Helpline. https://kidshelpline.com.au/teens/issues/your-brain-when-youre-anxious  
  5. GABA: The Neurobiology of Anxiety Disorders: Brain imaging, Genetics, and psychoneuroendocrinology:   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3684250/#:~:text=Neuroendocrine%20and%20Neurotransmitter%20Pathways&text=Increased%20activity%20in%20emotion%2Dprocessing,increased%20excitatory%20neurotransmission%20by%20glutamate.  
  6. A-Cfhc, L. C. M. C. L. (2020, July 2). The HPA Axis Dysfunction Diet: How to Use nutrition to support a balanced stress response. Chris Kresser. https://chriskresser.com/hpa-axis-dysfunction-diet/
  7. Gottschalk, M. G., & Domschke, K. (2017). Genetics of generalized anxiety disorder and related traits. Dialogues in Clinical Neuroscience, 19(2), 159–168. https://doi.org/10.31887/dcns.2017.19.2/kdomschke 
  8. Sarang, S., & Dave, S. (2022, October 12). Benefits of omega-3 fatty acids. Functional Nutrition  | iTHRIVE. https://www.ithrivein.com/blog/benefits-of-omega-3-fatty-acids  
  9. A Functional medicine approach to anxiety: testing, nutrition, & supplements. (2023, May 12). Rupa Health. https://www.rupahealth.com/post/a-functional-medicine-approach-to-anxiety   
  10. Epigenetic mechanisms: Don’t worry; be informed about the epigenetics of anxiety: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4939112/ 
  11. Dave, S. (2024, February 1). Common nutrient deficiencies that trigger anxiety disorders. Mental Health | iTHRIVE. https://www.ithrivein.com/blog/common-nutrient-deficiencies-that-trigger-anxiety-disorders
  12. Patino, E. (2023, November 27). Hypothyroidism and anxiety: what’s the connection? EverydayHealth.com. https://www.everydayhealth.com/hypothyroidism/hypothyroidism-anxiety-connection/ 
  13.  GoodRX - https://www.goodrx.com/conditions/irritable-bowel-syndrome/anxiety-ibs-irritable-bowel-syndrome-how-are-they-related 
  14. Can anaemia lead to anxiety and depression? (2023, October 12). Rupa Health. https://www.rupahealth.com/post/can-anemia-lead-to-anxiety-and-depression
Sharvi Dave
Research Associate

Experienced writer with a demonstrated history of working in the writing & editing history. skilled in writing, communication, digital marketing, & general aviation. Strong media & communication professional with a Bachelor of Science - Bs focussed in Aeronautics/Aviation/Aerospace Science & Technology General from Bombay Flying Club.

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.