Article Snapshot
- Anxiety is a normal response to a real or possible threat.
- The response can affect thoughts, heart rate, breathing, muscle tension, digestion, sleep and concentration.
- Anxiety becomes more concerning when it persists, feels out of proportion or interferes with work, relationships, sleep or ordinary activities.
- There is rarely one universal cause. Biology, learning, stress, health, hormones, sleep, substances and life circumstances can interact.
- Caffeine, alcohol, inconsistent sleep and inadequate recovery can amplify symptoms in some people.
- Regular meals, appropriate movement, slower breathing, sleep support and social connection may help lower the overall load, but they do not replace mental-health care when it is needed.
- Psychological therapy and medication are evidence-based options. Treatment should be matched to the person, the type of anxiety and its severity
Anxiety is a hard thing. It’s often very misunderstood, and it affects us both mentally and physically.
We have racing thoughts, all consuming worry, and often a continued sense that something is wrong. At this same time, our heart races up, our chest tightens, stomach turns, and our sleep can often be impacted too.
Anxiety involves real changes in the body, across our nervous system, hormones, breathing, digestion and more.
In this article, we’ll explain how anxiety is part of the body’s normal protection system. We’ll unpack what happens underneath anxiety, what influences it, and where chronic nervous system activation causes difficulty switching off or going out our day to day lives.
What Is Anxiety?
Anxiety is the body’s automatic response to a real or anticipated threat, and in the right context, it’s useful!
It sharpens our attention, increases energy and prepares us for the possible threat.
But… There’s a difference between occasional anxiety, and an anxiety disorder (or condition).
Normal anxiety usually has an identifiable trigger and settles when the situation passes. An anxiety condition is more likely when the fear or worry is persistent, difficult to control, out of proportion to the situation or strong enough to interfere with daily life (Healthdirect Australia, 2024).
Anxiety conditions, on the other hand, take different forms. They range from generalised anxiety disorder (GAD), panic disorder, social anxiety, specific phobias and agoraphobia. Obsessive-compulsive disorder and post-traumatic stress disorder are now classified separately in diagnostic systems, although anxiety can be a major symptom too.
In this day and age, Anxiety is fairly common too. The Australian Institute of Health and Welfare reported that approximately 17% of Australians aged 16–85 experienced an anxiety disorder during a recent 12-month period (AIHW, 2025).
We must ask though, why is it common? Because chronic anxiety affects our sleep, appetite, digestion, concentration, and bleeds into our relationships, work and our ability to function day-to-day.
What Happens in the Body During Anxiety?
I always like to describe anxiety as an alarm system, or an alert that something big or possibly scary is coming (and it’s normal).
Your brain continuously assesses the environment, your memories and sensations from inside the body. When it detects possible danger, it can activate systems designed to help you respond.
The sympathetic nervous system
The sympathetic branch of the autonomic nervous system prepares the body for action. Adrenaline and noradrenaline help increase alertness, heart rate and blood flow to working muscles.
We experience a range of common and probably familiar symptoms including:
- a racing or pounding heart
- quicker or shallower breathing
- sweating or feeling hot
- trembling
- tense shoulders, jaw or abdomen
- dry mouth
- nausea, urgency or “butterflies”
- dizziness or tingling
- difficulty sitting still.
These sensations can feel frightening, but they are often the body attempting to protect you (as more of a primal, natural response).
The stress-hormone system
The hypothalamic-pituitary-adrenal axis, usually shortened to the HPA axis, helps coordinate the longer stress response. It involves signaling between the brain and adrenal glands, including the release of cortisol.
Cortisol is not simply a “bad stress hormone”. It helps mobilise energy, regulate inflammation and support adaptation. Problems are more likely when stress is prolonged, recovery is inadequate or the alarm system keeps activating when no immediate action is required. Anxiety biology involves several interacting systems rather than a single chemical imbalance (Szuhany & Simon, 2022).
The anxiety feedback loop
Once the sympathetic nervous system and stress-hormone response are active, our attention becomes more sensitive to possible danger. This is useful if we need to respond to a genuine threat, but less helpful when the threat is an exam, a big speech or something uncertain that we cannot immediately resolve.
It can create a feedback loop:
- We notice the impending threat and begin anticipating what could go wrong.
- The alarm response increases, making the threat and related body sensations feel more important.
- Our attention keeps returning to the threat, while positive or reassuring information becomes harder to absorb.
- The continued focus reinforces the sense that danger is present, and anxiety escalates.
You might find when these feedback loop happens over and over, the anxiety feels bigger. Sometimes, we feel it in our gut, or the feelings can often feel paralysing.
This is because although cortisol plays a large part of this response, our interpretation, body sensations, breathing and our relationship with anxiety also need to be considered.
What happens when the stress response stays active?
A short stress response is adaptive. It helps us mobilise energy and respond to a challenge, this is the type of anxiety we want.
The downside appears when the alarm is activated repeatedly, the perceived threat does not resolve or there is not enough time for recovery.
The chronic work stress, worry, or copious amounts of cortisol spiking caffeine. These are all examples of things that keep us in the anxiety loop.
Over time, this can contribute to lighter or disrupted sleep, muscle tension, digestive changes, irritability, fatigue and difficulty concentrating. Those effects can then make us feel less resilient and more sensitive to the next stressor, creating another loop between anxiety and inadequate recovery.
The parasympathetic nervous system helps bring the body back towards rest, digestion and recovery. This system is the opposite of our sympathetic nervous system. We need more activation of the parasympathetic to pull us out of the anxiety loop, and there are many neurotransmitters that play a role with this switch too (such as GABA, which is essentially lowers Glutamate, which lowers cortisol).
I won’t delve too much into the nitty-gritty of neurotransmitters here. For a deeper explanation or understanding, see Substance Abuse and Neurotransmitters.
The Physical Feeling of Anxiety
The stress response temporarily changes priorities across the body.
Digestion may slow or become more active. Breathing patterns can change blood carbon-dioxide levels, contributing to light-headedness or tingling.
We can get tense muscles, and our sleep can often be lighter (because our body is literally on alert).
We can sometimes have a rabbit increase in appetite, or it can disappear all together, the physical symptoms can really range from person-to-person.
A lot of examples include:
- chest tightness or palpitations
- reflux, nausea, bloating, diarrhoea or constipation
- headaches or jaw tension
- fatigue combined with difficulty resting
- poor concentration or brain fog
- insomnia or unrefreshing sleep
- feeling detached, unreal or overwhelmed
Things That Make Anxiety Worse
Anxiety is often the result of several factors adding together. Yes it’s the original alarm system feedback loop, it begins with this.
But then we have a range of other lifestyle, dietary and biochemical factors that make anxiety worse.
Again, these can differ from person-to-person, just like the physical symptoms do.
Sleep and circadian rhythm
Anxiety can make it difficult to fall asleep, and keeps us out of that deep, restorative sleep we need.
In return, this sleep deprivation impairs of brain’s emotional regulation, resulting in even worse anxiety symptoms. The relationship with anxiety and sleep literally runs both directions like a viscous cycle (Royant-Parola, 2026).
A consistent wake time, morning light, a darker evening environment and enough opportunity for sleep can be useful foundations. Read more in Sleep Hygiene and Morning Sun and Circadian Rhythm.
Caffeine, alcohol and other substances
Caffeine increases alertness, but it can also increase shakiness, heart rate and anxious feelings. A meta-analysis found that caffeine increased anxiety in healthy participants, with a larger effect at higher doses (Liu et al., 2024).
Sensitivity varies, and yes, coffee is good for you, but we always need to look at dose, timing and your reoccurring symptoms and anxiety level.
Coffee has a wealth of benefits, but if your intake is incredibly high, it’s likely doing more harm than good for your quality of life.
Alcohol also may feel calming in the short term but can disrupt sleep and contribute to rebound anxiety as its effects wear off. Cannabis, stimulants, nicotine, some medications and withdrawal from alcohol or sedatives can also influence symptoms.
Never stop prescribed medication suddenly without professional guidance.
Food intake and nutritional status
Our food intake, particularly the frequency and how balanced our meals are, can have negative impact on our anxiety.
Examples include skipping breakfast, or consuming too much highly processed foods, that are practically void of nutrients and spike your blood sugar.
But no, it does not mean every anxious person has blood sugar issues, although, it can be part of the picture.
Nutrients also, such as iron, vitamin B12, folate, vitamin D, magnesium and zinc are important in maintaining normal nervous system function. Deficiency can exacerbate anxiety symptoms, and contribute to fatigue, restlessness, poor concentration or reduced resilience to stress.
Magnesium is often promoted as an anxiety solution. Particularly because it supports nervous system signaling, and promotes release of GABA, a neurotransmitter that activates our parasympathetic nervous system. Read more on the broader evidence and roles of Magnesium here: Magnesium: Why This Mineral Matters.
Gut symptoms and the gut-brain axis
The gut and brain communicate through neural, hormonal, immune and metabolic pathways. Stress can change digestion, while ongoing gastrointestinal symptoms can increase vigilance and distress.
Similar to sleep, this is another directional relationship where anxiety and stress impacts our gut, and then the state of our gut feeds back and worsen anxiety symptoms (Verma et al., 2024).
Some gut symptoms include altered bowel habits, reflux, and even persistent pain. Of course, ongoing symptoms always require assessment to rule out other diseases, such as coeliac disease, dairy intolerances or other serious health conditions.
Please note: Severe food restriction or narrowed diet to treat anxiety is not recommended, always seek guidance by a trained health professional, such as a Nutritionist or Naturopath.
Hormonal patterns
Some people notice predictable changes around the menstrual cycle, pregnancy, postpartum period or perimenopause. A systematic review found that symptoms can fluctuate across the menstrual cycle in several anxiety-related conditions (Green & Graham, 2022).
Fluctuations in oestrogen and progesterone can influence brain chemicals involved in mood and calming, including serotonin and GABA. For some people, the sharper hormonal shifts in the days before a period can temporarily increase anxiety, irritability, stress sensitivity and sleep disruption.
Hormone disruption can be a big deal. If we are experiencing Increased anxiety, stress resilience and sleep disruption, that is a trifecta of contributors that worsen the experience.
It’s often recommend to track cycle timing across 2-3 cycles to understand potential hormonal impacts. If you want to understand your hormones more, a 24-hour urinary test is most recommended to really understand what is happening undereath. A snapshot blood test can often be unreliable.
For more context on changing hormones, sleep and mood, see Unpacking Perimenopause.
Physical health and medications
Thyroid conditions, heart-rhythm problems, anaemia, respiratory illness, chronic pain and other health conditions, these can all amplify or produce anxiety-like symptoms. Some medicines or supplements may also contribute.
This does not mean your condition is the main driver of your anxiety, it’s likely a combination of contributors, so don’t worry.
This is why your GP or relevant health professional should always be considering the wider, more holistic picture. This is also particularly relevant when symptoms are new, severe, or rapidly changing.
Movement and recovery
Physical activity can support mood, sleep and stress regulation. A large overview of systematic reviews found that physical-activity interventions can improve symptoms of anxiety and psychological distress across adult populations (Singh et al., 2023).
This is actually a big win for physical activity, but, more is not always better here!
Someone who is exhausted, under-fuelled or highly sensitised to a racing heart may respond better to walking, resistance training, yoga or shorter sessions than another intense workout.
If you are on a 7 day workout bender trying to lose the weight, while severely undereating and juggling life in between, this is likely contributing to your anxiety picture.
Workload, uncertainty and digital input
Chronic stress = chronic cortisol activation = chronic fuel for your anxiety.
Months of deadlines, financial pressure, conflict, distressing news and constant notifications can repeatedly activate many of the same stress systems used during a physical threat.
Notice what happens after late-night work, doomscrolling, and also throwing the days stressors into the mix. You may also be repeatly checking symptoms or consuming large chunks of health content to find the cure to your anxiety.
The answer isn’t in the health content, it’s actually in the workload and stress your body is taking on.
I’m not saying to avoid all online information, but decide when it’s useful, and when it isn’t.
Humans were not evolved to know it all, so it’s okay to have uncertainty.
Relationships and emotional safety
Supportive relationships can buffer physiological stress. Being able to speak honestly, share practical load and feel safe with another person can change how manageable a situation feels.
On the other hand, anxiety can increase when emotions are suppressed, or the relationships in your home or work life just don’t feel safe or supportive.
Of course, we must always have a food first approach, but there is a point where this cannot solve the environmental or emotional driver.
If your home or work life puts you in serious danger, Call 000 or Lifeline 24-hour crisis support on 13 11 14
Tips to Reduce the Anxiety Load
That was all probably a lot to unpack if you read it all. The most important takeaway is that while everything appears connected, tying to fix it all will create more pressure.
Below are more pattern-like tracking tips to gradually resolve some of the anxiety you may be facing.
Track When Anxiety Happens
For one or two weeks, note:
- when anxiety appears
- what you were doing or thinking beforehand
- your sleep quality that previous night
- caffeine, alcohol and medication timing
- were you eaitng well or was there long gaps?
- menstrual-cycle (if relevant)
- digestive symptoms (and any food intake around it)
- stressful events (social, work, home)
- did anything make your anxiety better?
This list isn’t exhaustive, but some good areas to keep in the back of your mind.
Reduce one avoidable load
Did you find a pattern or notice something you can realistically change?
Great, pick one and stick to it for the next 2 weeks.
This could be dropping one coffee, eating more consistently, or having a hard line when it comes to work finish time to support healthy work life balance.
The key is to find something simple and make it easily actionable. I recommend reading Atomic Habits by James Clear if you want good tactical ways to incorporate habit simplicity.
Work with your body, not against it
Stress is actually inevitable, but the key is how we work with it.
Slower, comfortable breathing may help reduce physiological arousal. A meta-analysis found respiratory interventions can reduce anxiety, although the methods and quality of studies vary (Leyro et al., 2021).
Try a gentle exhale-focused pattern without forcing a very deep breath. If breathwork makes you more uncomfortable, stop and use another grounding strategy, such as feeling your feet on the floor, naming objects in the room or walking slowly.
The key here is activating that parasympathetic nervous system to pull us out of that fight-or-flight, high anxiety state.
Box breathing is also a good tactic, which involves 4 slow breaths in, hold for 4, 4 slow breaths out, hold for 4. Repeat this 6-8 times a session, 2 times a day (or when needed).
Cover the foundations (as best as you can)
Sleep, regular meals, daylight, appropriate movement, time outdoors and meaningful contact with other people.
I won’t unpack too much here, but these are your foundations for health and really essential to supporting healthy quality of life.
Again, maybe you can pick one, but really, they’re kind of non-negotiable if you want to reduce your anxiety long-term.
Get the right kind of help
Psychological therapies, including cognitive behavioural therapy and graded exposure, are established treatments for anxiety. Medication may also be appropriate for some people.
Treatment should be discussed with a GP or mental-health professional and matched to your symptoms, preferences and health history if you decide to go down the medication route (Healthdirect Australia, 2024; Szuhany & Simon, 2022).
Nutrition and naturopathic care can sit alongside mental-health treatment as well.
If you are struggling to tick off the foundations, or just stuck, this type of care can really help. Naturopathic care involves supporting your diet, sleep, stimulant use, check deficiencies and other health factors.
When to Seek Professional Help
Speak with a GP or mental-health professional when anxiety:
- is persistent or getting worse
- causes panic attacks
- interferes with sleep, work, study or relationships
- leads you to avoid important activities
- causes increasing reliance on alcohol, sedatives or other substances
- comes with significant depression, hopelessness or difficulty coping
- begins suddenly or with concerning physical symptoms
- you have episodes of suicidal thoughts
Call 000 if you or someone else is in immediate danger. If you are feeling overwhelmed or having difficulty staying safe, Lifeline provides 24-hour crisis support on 13 11 14 (Lifeline Australia, n.d.)..
Frequently Asked Questions
What is the difference between stress and anxiety?
Stress is commonly linked to an identifiable demand, such as a deadline, conflict or illness. Anxiety can continue after the immediate stressor has passed or may focus on a possible future threat. They overlap, and ongoing stress can increase anxiety.
Can anxiety cause physical symptoms?
Yes. Anxiety can affect heart rate, breathing, muscles, digestion, sleep, temperature, concentration and balance. New or severe symptoms should still be medically assessed rather than automatically attributed to anxiety.
Can caffeine make anxiety worse?
Yes, particularly at higher doses or in sensitive people. Consider the total amount from coffee, tea, energy drinks, pre-workout products and some medicines. Reduce gradually if intake is high.
Is anxiety caused by a nutrient deficiency?
Usually not by one nutrient alone. Iron, vitamin B12, folate, vitamin D, magnesium and zinc support normal physiology, and deficiency can overlap with anxiety-like symptoms. Assessment should consider food intake, health history and appropriate testing.
Can gut problems cause anxiety?
The gut and brain communicate in both directions. Digestive symptoms may increase distress, and anxiety can change gut motility and sensitivity. This relationship is real but complex; it should not be reduced to one microbe or a universal probiotic.
When does anxiety become a disorder?
Anxiety may meet the threshold for a disorder when it is persistent, difficult to control, out of proportion to the situation and causes distress or interferes with daily functioning. A qualified health professional can assess this properly.
References
Australian Institute of Health and Welfare. (2025, May 20). Prevalence and impact of mental illness. https://www.aihw.gov.au/mental-health/overview/prevalence-and-impact-of-mental-illness
Green, S. A., & Graham, B. M. (2022). Symptom fluctuation over the menstrual cycle in anxiety disorders, PTSD, and OCD: A systematic review. Archives of Women’s Mental Health, 25(1), 71–85. https://doi.org/10.1007/s00737-021-01187-4
Healthdirect Australia. (2024, September). Anxiety. https://www.healthdirect.gov.au/anxiety
Leyro, T. M., Versella, M. V., Yang, M.-J., Brinkman, H. R., Hoyt, D. L., & Lehrer, P. (2021). Respiratory therapy for the treatment of anxiety: Meta-analytic review and regression. Clinical Psychology Review, 84, 101980. https://doi.org/10.1016/j.cpr.2021.101980
Lifeline Australia. (n.d.). Lifeline crisis support. https://www.lifeline.org.au/get-help/national-services/lifeline-crisis-support
Liu, C., Wang, L., Zhang, C., Hu, Z., Tang, J., Xue, J., & Lu, W. (2024). Caffeine intake and anxiety: A meta-analysis. Frontiers in Psychology, 15, 1270246. https://doi.org/10.3389/fpsyg.2024.1270246
Royant-Parola, S. (2026). Sleep disturbances in anxiety disorders: State of the art and management. L’Encéphale, 52(3S), S46–S50. https://doi.org/10.1016/j.encep.2026.02.011
Singh, B., Olds, T., Curtis, R., Dumuid, D., Virgara, R., Watson, A., Szeto, K., O’Connor, E., Ferguson, T., Eglitis, E., Miatke, A., Simpson, C. E. M., & Maher, C. (2023). Effectiveness of physical activity interventions for improving depression, anxiety and distress: An overview of systematic reviews. British Journal of Sports Medicine, 57(18), 1203–1209. https://doi.org/10.1136/bjsports-2022-106195
Szuhany, K. L., & Simon, N. M. (2022). Anxiety disorders: A review. JAMA, 328(24), 2431–2445. https://doi.org/10.1001/jama.2022.22744
Verma, A., Inslicht, S. S., & Bhargava, A. (2024). Gut-brain axis: Role of microbiome, metabolomics, hormones, and stress in mental health disorders. Cells, 13(17), 1436. https://doi.org/10.3390/cells13171436