What Happens to Your Body When Anxiety Stays

Many of us know anxiety as a mental experience — the racing thoughts, the worry, the sense that something is off. Some of us have already connected it to how we feel physically: the tight chest, the unsettled stomach, the tension that won't release. But there's a layer that often goes unseen — what anxiety is actually doing inside the body, at the level of organs and systems, when it becomes a long-term companion. This post gets a little more into the science than usual. It's worth it.

If you haven't read our earlier post on what anxiety actually is, it's a good place to start — it covers the nervous system mechanism that drives everything we're about to look at here. This post takes that a layer deeper: not what anxiety is, but what it does — to the body, over time, when it becomes a long-term state rather than an occasional visitor.

When the Body Stays on Alert

When anxiety activates the nervous system, two hormones do most of the immediate work: cortisol and adrenaline. Adrenaline acts first — it's what creates the rapid heart rate, the quickened breath, the sudden alertness. Cortisol follows, sustaining the response and mobilising the body's resources for what the nervous system has registered as a threat.

In the short term, this is the system working exactly as it should. The hormones do their job, the threat passes, and the body returns to rest.

The difficulty comes when the threat doesn't pass — or when the nervous system has learned to stay in a state of readiness even when the immediate situation has resolved. Cortisol and adrenaline continue to circulate. The body stays in emergency mode. And over time, that sustained activation begins to affect the body's systems in ways that go far beyond how anxiety feels in the moment.

What follows looks at six of the body's systems and what sustained anxiety can do to each. Some of this may connect directly to something you're already experiencing. Some may be new. Either way, the picture that emerges is worth understanding — because understanding it is the first step toward doing something about it.

What Anxiety Does to Your Metabolism and Weight

Metabolism is the process by which the body converts food into energy — and cortisol sits right at the center of it. When cortisol stays elevated, it changes how the body processes glucose, fat, and protein. Instead of running efficiently, the body stays in a kind of permanent emergency mode — burning and storing energy as if a crisis is always just around the corner.

The practical effects of this are significant. Blood sugar stays higher than it needs to be. The body keeps storing fat — particularly visceral fat, the fat stored deep in the abdomen — because it's still behaving as if it needs to fuel an emergency. Cravings for sugary and high-fat foods increase for the same reason: the body is trying to maintain energy reserves for a threat that hasn't passed. [1][2]

Over time, this chronic state contributes to insulin resistance — the body becoming less responsive to insulin's signals — which raises the risk of type 2 diabetes. Weight that doesn't shift despite changes in diet or exercise may not be a willpower issue. It may not even be a metabolism issue in the conventional sense. It may be a nervous system issue. [3]

Insulin resistance matters beyond weight and diabetes. It's a thread that runs through many of the body's systems — and we'll come back to it at the end of this post.

What Anxiety Does to Your Cardiovascular System

The heart is particularly sensitive to adrenaline. In the short term, adrenaline raises heart rate and increases blood pressure — pushing blood quickly to the muscles to prepare for action. That's the system working as designed.

But when adrenaline and cortisol stay elevated over time, blood pressure doesn't return to its resting baseline. It stays raised. And sustained high blood pressure — even at levels that might not yet trigger a diagnosis — puts ongoing strain on the walls of the arteries. Over time, this contributes to a higher risk of heart disease, including arrhythmias — irregular heartbeats — and coronary artery disease. [4][5]

Tension headaches and migraines can also be a cardiovascular expression of chronic stress, as the nervous system affects blood flow to the brain in ways that show up as pain rather than pressure.

For many people, these symptoms arrive without any obvious connection to anxiety. A racing heart, high blood pressure, frequent headaches — these are often investigated and treated as standalone conditions, without anyone asking what the nervous system might have to do with them.

What Anxiety Does to Your Immune System

The immune system and the stress response are deeply connected — and not in a way that works in our favor when stress becomes chronic.

In the short term, cortisol actually has an anti-inflammatory effect. That's useful in a genuine emergency — it keeps the immune system from overreacting while the body deals with an immediate threat. But when cortisol stays elevated over time, it begins to suppress immune function rather than regulate it. The body produces fewer of the cells it needs to fight infection, and the immune response becomes less effective overall.

The practical result is familiar to many people under chronic stress: getting sick more often, taking longer to recover, feeling run down in a way that rest doesn't quite fix. Wounds heal more slowly. The body's ability to repair itself is quietly compromised.

There's another layer worth noting. Chronic stress also drives systemic inflammation — a low-level, ongoing inflammatory state that quietly affects the whole body. This kind of inflammation, sustained over time, is increasingly linked to a wide range of serious conditions, from cardiovascular disease to autoimmune disorders. [6][7]

What Anxiety Does to Your Brain

It might seem counterintuitive that anxiety — a state of heightened alertness — could impair the very organ driving it. But chronic cortisol exposure has measurable effects on the brain, particularly in regions involved in memory and learning.

The hippocampus, which plays a central role in forming and retrieving memories, is especially vulnerable to sustained cortisol exposure. Over time, chronically elevated cortisol can cause the hippocampus to shrink — a process called atrophy — which affects the ability to concentrate, retain new information, and access memories clearly. The brain fog, forgetfulness, and difficulty focusing that many people experience during periods of prolonged stress or anxiety aren't imagined. They have a physical basis. [8]

There's a longer-term dimension worth naming here. Research is increasingly pointing to a connection between chronic cortisol dysregulation and the risk of cognitive decline over time — including dementia. We'll come back to this at the end of the post, when we look at the thread that connects many of these systems together. [9]

What Anxiety Does to Your Gut

The digestive system has its own extensive nervous system, deeply connected to the brain and highly responsive to stress hormones. When cortisol stays elevated, digestion slows or becomes erratic. The gut lining becomes more permeable, affecting how nutrients are absorbed. Gastric acid production increases, raising the risk of discomfort, reflux, and over time, ulcers.

For many people, gut symptoms are among the first signs that the nervous system is under sustained pressure — and among the last to be connected to anxiety as a cause.

If you'd like to go deeper on the gut-brain connection, we've written about it here and here.

What Anxiety Does to Your Sleep

Sleep is where the body repairs, consolidates memory, regulates hormones, and resets the nervous system. It's also one of the first things chronic anxiety disrupts — and one of the most consequential.

Cortisol and sleep operate on opposing rhythms. Cortisol is naturally highest in the morning, helping the body wake and engage with the day, and lowest at night, allowing the body to wind down and rest. When cortisol stays chronically elevated, that rhythm flattens. The body doesn't get the signal to slow down. Sleep becomes harder to initiate, easier to disrupt, and less restorative even when it happens.

The difficulty is that poor sleep then feeds back into the stress response. A sleep-deprived nervous system is more reactive, more easily triggered, and less able to regulate cortisol effectively. Anxiety drives poor sleep. Poor sleep drives more anxiety. The loop runs in both directions. [10][11]

For many people this feels like a separate issue from their anxiety — something to address on its own, with sleep aids or better sleep hygiene. But the nervous system is often at the root of both.

The Thread Running Through All of It

Across the systems we've just covered — metabolism, cardiovascular, immune, brain, gut, sleep — there's a common mechanism quietly connecting many of them: insulin resistance.

When the body becomes less responsive to insulin's signals over time, the effects ripple outward. Cardiovascular risk increases. Inflammation intensifies. And there's a growing body of evidence linking long-term insulin resistance to cognitive decline — including dementia. Some researchers now describe Alzheimer's disease as a form of metabolic dysfunction in the brain, so consistent is the connection between sustained insulin dysregulation and the health of the brain over time. [12]

Kidney disease follows a similar thread. Diabetes — itself a downstream consequence of long-term insulin resistance — is the leading cause of kidney disease. What's increasingly being demonstrated is that addressing insulin resistance directly, rather than managing kidney decline as an inevitable trajectory, can change the course of the disease. The work of Dr. Jason Fung, a nephrologist who has documented the reversal of kidney disease through targeting insulin resistance at its root, is one of the more compelling examples of this in clinical practice. [13]

These aren't separate, unrelated conditions that happen to coexist. They're often expressions of the same underlying state — a nervous system that has been running in emergency mode for too long.

And that matters — because it means addressing the nervous system isn't just about feeling less anxious. It's about the body's long-term health.

What This Makes Possible

What this picture actually points to is something worth naming.

If a nervous system running in emergency mode is at the root of so much of this, then working with the nervous system is one of the most direct things you can do. Rather than managing symptoms one by one — the sleep, the weight, the gut, the blood pressure — it addresses the state that's driving all of them.

For some of us, this is a new way of thinking about it. And it's where the next post picks up — what it actually looks like to work with the nervous system directly, and why that approach reaches places that other interventions often don't.

This may be the beginning of a different conversation with your body — one that moves from "why won't this just get better" to "I can actually do something about this."

Curious to Work With This Directly?

If something in this post resonates, a free consultation is a good place to start. It's a no-pressure conversation about what you're experiencing and whether this kind of work might be a fit.

Book your free consult here → brooklynhypnotherapy.nyc/book-online

Spring Haughton is a certified clinical hypnotherapist and NLP practitioner. She works with clients virtually on anxiety, stress, gut-brain health, relationships, sleep, and personal growth.

References

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[2] Lengton R, Schoenmakers M, Penninx BWJ H, Boon MR, van Rossum EFC. (2025). Glucocorticoids and HPA axis regulation in the stress-obesity connection: A comprehensive overview of biological, physiological and behavioural dimensions. Clinical Obesity, 15(2), e12725.

[3] Lisco G, Giagulli VA, De Pergola G, Guastamacchia E, Jirillo E, Vitale E, Triggiani V. (2024). Chronic stress as a risk factor for type 2 diabetes: endocrine, metabolic, and immune implications. Endocrine, Metabolic & Immune Disorders — Drug Targets, 24(3), 321–332.

[4] Munir LZ, du Toit EF. (2024). Impact of chronic psychological stress on cardiovascular disease risk: A narrative review. Heart and Mind, 8(4), 268–278.

[5] Hatamova M, Rizk M, Rattan K, et al. (2026). Chronic stress, diabetes, and cardiovascular disease: epidemiologic evidence, pathogenetic insights, and therapeutic strategies. Cureus, 18(1), e102108.

[6] Alotiby A. (2024). Immunology of stress: A review article. Journal of Clinical Medicine, 13(21), 6394.

[7] Balakin E, Yurku K, Ivanov M, Izotov A, Nakhod V, Pustovoyt V. (2025). Regulation of stress-induced immunosuppression in the context of neuroendocrine, cytokine, and cellular processes. Biology, 14(1), 76.

[8] Lupien SJ, de Leon M, de Santi S, Convit A, Tarshish C, Nair NPV, et al. (1998). Cortisol levels during human aging predict hippocampal atrophy and memory deficits. Nature Neuroscience, 1(1), 69–73.

[9] Almalki DF, Alkabkabi RA, Wayyani RA, et al. (2026). Chronic stress, cortisol dysregulation, and neurodegenerative vulnerability: mechanistic pathways linking HPA-axis dysfunction to Alzheimer's disease risk. Frontiers in Aging Neuroscience, 18, 1883880.

[10] Ungurianu A, Marina V. (2025). Melatonin and cortisol suppression and circadian rhythm disruption in burnout among healthcare professionals: A systematic review. Clinics and Practice, 15(11), 199.

[11] Ungurianu A, Marina V. (2025). The biological clock influenced by burnout, hormonal dysregulation and circadian misalignment: A systematic review. Clocks & Sleep, 7(4), 63.

[12] Wang S, Shi Y, Xin R, Kang H, Xiong H, Ren J. (2025). Exploring the role of insulin resistance in bridging the metabolic syndrome and Alzheimer's disease: a review of mechanistic studies. Frontiers in Endocrinology, 16, 1614006.

[13] Fung J. (2018). The Diabetes Code: Prevent and Reverse Type 2 Diabetes Naturally. Greystone Books.