An article written by Dr Edward Leatham, Consultant Cardiologist

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“Between stimulus and response there is a space. In that space is our power to choose our response. In our response lies our growth and our freedom.”
– Viktor E. Frankl

Stress is an unavoidable part of modern life. We encounter it at work, at home, in traffic, and even while reading the news. Although we often discuss stress casually, its impact on the human body is profound—particularly on the cardiovascular system. In this article, we will explore how stress affects the heart and blood vessels, drawing on clinical insights, expanding scientific knowledge, and practical stress-management strategies. By the end, you will see why stress is a critical factor in any heart health strategy, along with steps you can take to mitigate its harmful effects.

1. Flight and Fright Responses: An Integral Part of Human Physiology

From an evolutionary standpoint, our bodies are equipped with a “fight or flight” mechanism that has helped humans (and other animals) survive for millennia. When our senses detect a threat—whether an actual physical danger or a psychological stressor—our sympathetic nervous system ramps up:

• Heart rate increases to deliver blood more rapidly around the body.
• Blood pressure rises, supporting higher cardiac output.
• Pulse rate quickens, all under the influence of stress hormones such as adrenaline (epinephrine) and cortisol.
• Blood glucose elevates, ensuring a ready supply of “rocket fuel” for skeletal muscles and the heart.

In the wild, this surge of energy makes sense. It prepares an animal to either fight the danger or flee. However, in modern life, the stressor is less likely to be a wild animal and more likely to be a looming work deadline or financial worry. The physiological response, though, remains largely unchanged and can easily become chronic if the stressor persists. Over time, prolonged activation of “fight or flight” can strain the cardiovascular system, manifesting as high blood pressure, palpitations, and other cardiac symptoms.

2. Symptoms Influenced by Stress in the Cardiology Clinic

Stress is not just a mental or emotional phenomenon; it can produce very real physical symptoms. In a cardiology clinic, patients often present with complaints that can be closely tied to stress, such as:

1. Palpitations – Sensations of a fast or thumping heartbeat.
2. Chest Pains – Sometimes caused by chest wall tension rather than underlying coronary artery disease.
3. Headache – Can stem from transiently raised blood pressure.
4. Breathlessness – Often related to hyperventilation when anxious.

Because these symptoms overlap with those of significant heart disease, they can understandably cause alarm. It is thus crucial to investigate them, rule out serious conditions, and address any stress-related factors.

3. What Diseases Are Proven to Be Caused by Stress?

The question of whether stress directly causes any specific disease is surprisingly difficult to answer scientifically. Stress is intangible, with no universal metric for measurement, and people respond to stressors differently. Furthermore, when people feel stressed, they often adopt unhealthy habits—smoking, poor diet, increased alcohol intake—that themselves contribute to illness. This interplay obscures whether stress alone is the culprit or if it merely nudges people towards other risk factors.

Despite the lack of absolute proof, many clinicians and researchers acknowledge that stress can:

• Worsen existing cardiovascular conditions.
• Contribute to high blood pressure.
• Aggravate arrhythmias and palpitations.
• Disrupt metabolic processes, potentially aiding in the development or progression of pre-diabetes and diabetes.

In modern cardiology practice, the focus is more on managing and mitigating stress-related symptoms and behaviours rather than trying to pinpoint stress as the singular cause of any one disease.

4. Medical Conditions Affected by Stress: Hypertension

A Revealing Case Study on Blood Pressure and Work-Related Stress

A telling illustration of stress’s influence on cardiovascular health comes from a patient I have treated for over a decade for hypertension. As he entered his 70s, he decided to relinquish control of his long-established family business and spend his remaining years travelling. Freed from the constant pressures of running a business, his blood pressure showed a remarkable transformation.

Within six months, he no longer needed any of his antihypertensive medications because his blood pressure was consistently well controlled. The logical conclusion was that a substantial reduction in stress had led to his dramatic improvement.

Regrettably, his stress-free life was short-lived. When the family business started to decline without his oversight, he returned to manage the crisis. Almost instantly, his blood pressure surged—this time to even higher levels than before. It required three or four different blood pressure medications, at significantly higher doses, to bring it under control. Although the major business problems were eventually resolved, he continued to need multiple medications to maintain a safe blood pressure range.

This case exemplifies how stress—even if challenging to quantify—can exert a potent influence on the cardiovascular system. It also suggests that periods of intense stress might have lasting, possibly irreversible, effects on blood pressure regulation and the sympathetic nervous system.

5. Palpitations: When “Butterflies” Become Heart Pounding

“Palpitation” is a broad term describing an individual’s awareness of their own heartbeat. It may feel like extra beats, missed beats, a flutter, or a racing heart rate. These can be triggered by:

• Ventricular and atrial ectopic beats (extra beats originating from various parts of the heart).
• Arrhythmias such as paroxysmal atrial fibrillation.
• Physiological responses like sinus tachycardia during stress or anxiety.

5.1 Stress, Palpitations, and Ectopic Beats

Most people recognise the fluttery feeling in the stomach—often called “butterflies”—before a stressful event such as an exam or a major presentation. This sensation largely stems from a surge of adrenaline, which not only raises heart rate but can also cause occasional extra or “skipped” beats known as ectopics. While these extra beats are frequently benign, they can be distressing enough to prompt a cardiology consultation. In some cases, they may point towards:

• Cardiomyopathy
• Uncontrolled hypertension
• Coronary artery disease
• More serious arrhythmias

A thorough assessment, often involving ECG monitors such as a Holter device or a Preventice ECG patch, can help differentiate harmless ectopics from more concerning arrhythmias. In addition, patients with conduction issues—like Mobitz II block or Wenckebach heart block—may experience palpitations or dizziness, and monitoring with advanced devices (e.g., Preventice, or other external loop recorders) can clarify how stress exacerbates these conditions.

6. Stress, Hormones, and Blood Glucose

6.1 The Fight-or-Flight Response

Central to the stress response is the body’s production of cortisol and adrenaline (epinephrine). These hormones:

• Raise blood glucose levels, providing immediate energy for a potential fight or flight.
• Elevate heart rate and blood pressure, priming the body for sudden physical exertion.
• Mobilise glycogen stores to ensure muscles (including the heart) have enough fuel.

Though these responses were invaluable for survival in the past, today’s stressors—work deadlines, family obligations, financial issues—rarely require literal fighting or fleeing. The result is that our bodies repeatedly surge with adrenaline and cortisol, often with nowhere for the energy to go. Chronic exposure to these hormones can contribute to persistently raised blood pressure and blood glucose, which in turn places extra stress on arteries and the heart muscle.

6.2 The Vicious Cycle of Poor Sleep

Poor or insufficient sleep also plays a critical role in the stress cycle. Inadequate rest can cause elevated cortisol levels the following day, exacerbating both blood pressure and blood glucose dysregulation. This sets up a negative feedback loop:

1. Stress contributes to poor sleep.
2. Poor sleep boosts cortisol levels.
3. Higher cortisol leads to more spikes in blood pressure and glucose.
4. Fatigue intensifies stress further.

Over weeks, months, or years, this cycle can foster chronic hypertension, raise the risk of metabolic syndrome, and increase the likelihood of arrhythmias such as atrial fibrillation.

7. Diabetes and Glucose Dysregulation in Heart Disease

7.1 Overt Diabetes vs Subtle Glucose Spikes

For more than a century, it has been known that people with diabetes—whether Type 1 or Type 2—are at higher risk for coronary heart disease. Even when blood glucose is carefully managed, long-standing diabetes still predisposes individuals to arterial disease. Diabetes is conventionally diagnosed using criteria such as:

• Haemoglobin A1c (HbA1c)
• Fasting blood glucose
• Oral glucose tolerance tests

However, the growing use of continuous glucose monitors (CGMs) reveals a more nuanced picture. Many individuals who do not meet the formal criteria for diabetes still experience significant post-meal spikes in blood glucose, sometimes exceeding 10 mmol/L (180 mg/dL). Whether these fleeting elevations lead to increased cardiovascular risk is currently being investigated. Preliminary evidence suggests that repeated spikes could cumulatively harm the arteries and the heart over time.

7.2 New Glucose-Lowering Medications with Cardiac Benefits

Recent advances in medication have drawn renewed attention to glucose regulation in heart disease. Two major classes of drugs are particularly noteworthy:

1. SGLT2 inhibitors (sometimes confused with “GLP-2” but correctly known as SGLT2): These have demonstrated substantial benefits in reducing hospitalisations for heart failure—even in people without a formal diabetes diagnosis.
2. GLP-1 receptor agonists (e.g., semaglutide): These show impressive reductions in major cardiovascular events, again extending beyond diabetic populations.

While the established principle is that individuals with diabetes face higher cardiovascular risk, these new therapies raise questions about whether milder glucose metabolism problems might also promote or worsen heart conditions. Many cardiologists now wonder if subtle glucose dysregulation—stress-related or otherwise—could be an underestimated factor in heart disease.

8. The Growing Importance of Glucose Monitoring in Cardiology

8.1 Drawing Parallels to Ambulatory Blood Pressure Monitoring

Ambulatory blood pressure monitoring has been a mainstay of hypertension management for decades. Patients wear a device that measures blood pressure multiple times over 24 hours, capturing daily patterns through work, exercise, and sleep. Similarly, CGMs have moved beyond the realm of diabetes and are now finding a place in cardiology:

• Short-Term CGM Trials: Patients, including those without diabetes, wear a CGM for a week or two to track how meals, sleep, and stress affect their blood glucose.
• Identifying Triggers: Stressful meetings, late-night emails, or high-carbohydrate meals can be pinpointed as triggers for glucose spikes.
• Adjusting Lifestyle: Informed by CGM data, people can choose lower-glycaemic foods, schedule meals earlier, and implement stress management strategies to stabilise glucose.

By combining blood pressure and glucose monitoring, cardiologists gain a more comprehensive view of how stress impacts the cardiovascular system. This broader perspective can guide treatment plans that integrate lifestyle changes, stress management, and, if needed, medication.

9. Atrial Fibrillation, Glucose Metabolism, and Stress

9.1 How Stress and Glucose Spikes Might Contribute

Atrial fibrillation (AF) is the most common sustained arrhythmia, affecting millions worldwide. Many patients experience paroxysmal AF, which flares unpredictably, while others have persistent or permanent AF. During stress, the surge of adrenaline and subsequent elevation of blood glucose could aggravate or trigger arrhythmias in susceptible individuals.

• Increased Adrenaline further stimulates the heart, potentially facilitating AF in those with an irritable atrial substrate.
• Higher Glucose may promote inflammatory pathways or electrolyte imbalances that predispose to arrhythmias.

Although not every episode of AF is caused by stress, enough patients report an association to make stress management a standard recommendation—especially when episodes occur during anxious periods or after poor sleep.

10. Stress-Related Ectopic beats and Treatments

Not all forms of irregular heartbeat are benign. Certain common extra heart beat disturbances, such as ventricular and atrial ectopics, can become symptomatic under stress. Only some of these rhythms have structural or electrical origins, however stress can exacerbate symptoms like palpitations or dizziness in anyone with a predisposition.

10.1 Beta-Blockers and Other Pharmacological Approaches

Since adrenaline can provoke or worsen ectopic beats and elevate both heart rate and blood pressure, beta-blockers remain a cornerstone in:

• Reducing the heart’s response to adrenaline by blocking beta-receptors.
• Controlling heart rate in stress-related arrhythmias.
• Managing hypertension aggravated by chronic stress.

Beta-blockers are particularly advantageous for individuals whose cardiovascular parameters are highly sensitive to adrenaline. Yet, with emerging evidence on glucose dysregulation, many cardiologists are adopting a more holistic treatment strategy—one that addresses not just the heart’s rhythm and rate but also the metabolic and emotional drivers of stress.

11. Stress Management: Tackling the Root

11.1 Removing Oneself from Stressful Situations

In an ideal world, patients could simply eliminate their chief sources of stress—similar to the patient in the case study who travelled instead of managing his family business. Unfortunately, for most people, it is not so simple. Work, mortgages, and family responsibilities cannot simply be abandoned.

11.2 Mind-Body Interventions

When avoidance is not possible, doctors often recommend stress management techniques, such as:

• Mindfulness Meditation: Focusing on the present moment can help lower heart rate, reduce stress hormones, and improve overall autonomic balance.
• Yoga and Tai Chi: These activities blend gentle physical postures, controlled breathing, and mental focus. Research has linked them to better blood pressure control and improved heart rate variability.
• Therapy or Counselling: Talking therapies, particularly Cognitive Behavioural Therapy (CBT), offer coping strategies for reframing stressful thoughts and reducing emotional reactivity.
• Regular Exercise: Moderate aerobic exercise releases endorphins, dampens cortisol production, and supports healthy blood pressure and glucose metabolism.

These techniques are increasingly endorsed by preventive cardiologists who recognise that emotional well-being and cardiovascular health are tightly interwoven. Even modest stress reduction can yield measurable physiological benefits, such as reduced ectopic beats, improved blood pressure readings, and possibly fewer arrhythmic episodes.

12. Measuring Stress: Limitations and Future Directions

Although we discuss various signals of stress—such as rises in blood pressure, heart rate, glucose, and arrhythmias—there is still no single, universally accepted measure of stress. People have wildly divergent thresholds, coping styles, and physiological responses. Two individuals facing the same challenges may exhibit entirely different emotional and bodily profiles.

Nevertheless, technological strides are underway:

• Wearable heart rate monitors: Many smartwatches and fitness trackers measure heart rate variability (HRV), a useful indicator of autonomic balance. A declining HRV and increase in resting heart rate may be signals of rising stress.
• CGMs – increasingly of interest in the wellness marketplace: these measure blood glucose linked to insulin secretion and can be a useful biomarker linked to stress hormones, by the action of elevated cortisol on glucogenesis. Many patients will observe higher glucose responses to carbohydrate intake during stressful periods than when calm. This knowledge can lead to altering food intake groups (less carbohydrate nor fats and protein) on stressed days. 
• Continuous Cortisol Monitoring: Not yet routine, but under development. If perfected, it could provide real-time data about the body’s stress hormone levels.

For now, clinicians rely on a blend of patient self-reports, surrogate physiological markers, and clinical judgment to gauge how stress is affecting an individual’s heart health.

13. Advanced Monitoring: From Preventice Patches to Aktiia Wrist Bands

Beyond conventional Holter monitors, the landscape of cardiac and blood pressure monitoring is expanding with innovative technologies:

• ECG Monitors: Lightweight patches offering extended ECG tracking. These are particularly useful in diagnosing intermittent arrhythmias like atrial fibrillation or frequent ectopics that may correlate with stress or other triggers.
• Wrist Band BP Monitoring: A novel wrist-worn device that continuously monitors blood pressure throughout the day and night, giving insights into the effects of daily stressors.
• Digital health assistant: an emerging platform that integrates data on risk factors, imaging, and wearable sensors to provide a more comprehensive cardiovascular risk assessment.

While these tools are still evolving, they herald an era in which clinicians can track real-world data and correlate it with patients’ stress levels and daily activities, leading to ever more personalised treatment.

14. Synthesis and Conclusion

Stress is a critical yet often under-recognised factor in heart disease. From the patient whose blood pressure normalised when he took a break from business pressures—only to surge even higher when he returned—to the mechanistic links between cortisol, adrenaline, blood glucose, and arrhythmias, one message emerges clearly: the body’s stress response can cause tangible harm if left unchecked.

Complicating matters is the increased recognition that people who are not classed as diabetic may still exhibit significant post-meal glucose spikes, especially during periods of heightened stress or lack of sleep. These spikes could foster structural and electrical changes in the heart, triggering or exacerbating arrhythmias like atrial fibrillation. Emerging medication classes—such as GLP-1 receptor agonists (e.g., semaglutide) and SGLT2 inhibitors—hold promise for improving cardiovascular and metabolic health, but the mainstay of any robust prevention or management plan remains lifestyle: a balanced diet, regular exercise, quality sleep, and effective stress management.

Modern technology enables a clearer picture of day-to-day fluctuations in blood pressure, glucose, and heart rhythm. Collaboration between patient and doctor can now be more data-driven than ever. By pinpointing triggers—be it a stressful meeting or a late-night flurry of emails—patients can adjust their behaviour accordingly. We may see continuous blood pressure and glucose monitoring become standard practice, parallel to how ambulatory blood pressure monitoring has been for decades.

15. Practical Guidance for Patients

1. Identify Major Stressors
   • If possible, remove yourself from high-stress environments. If not, actively explore stress management strategies like mindfulness, meditation, or therapy.
2. Monitor Blood Pressure and Heart Rate at Home
   • Home monitoring, or using a device such as the Aktiia wrist band, provides insights into daily patterns. Share this information with your healthcare provider to refine your treatment.
3. Consider a Continuous Glucose Monitor (CGM)
   • Even without a diabetes diagnosis, a CGM trial can help you see how meals, sleep, and stress affect your blood sugar. This can guide both diet and lifestyle modifications.
4. Optimise Your Sleep
   • Poor sleep elevates cortisol, thereby raising blood pressure and blood glucose. Good “sleep hygiene”—including a regular bedtime, limiting caffeine, and avoiding screens late at night—can substantially improve heart health.
5. Try Lifestyle Changes Before Increasing Medication
   • While medication is essential in many cases, even small lifestyle changes—such as improved diet, more exercise, or meditation—can yield significant improvements and might reduce the need for multiple medications.
6. Maintain an Open Dialogue with Your Healthcare Team
   • Report any unusual patterns in heart rate, blood pressure, or blood sugar promptly. Early discussions can lead to timely adjustments in treatment, possibly preventing more severe complications.

Final Thoughts

Stress is far more than a vague psychological concept. It is a tangible physiological process that elevates hormones, disrupts glucose regulation, inflames blood vessels, and triggers arrhythmias. As shown by the case study of the patient whose blood pressure returned to normal during a period of low stress, reducing stress—even temporarily—can have striking benefits. The challenge lies in implementing sustainable changes in a world filled with pressures. Yet with the convergence of emerging technology, modern cardiology, and a holistic understanding of stress physiology, the prospects for effectively managing stress-related heart issues are better than ever.

Ultimately, the heart does not exist in isolation. It responds minute by minute to signals from the brain, hormones, and external stimuli. By recognising the interdependent relationship between emotional well-being, glucose metabolism, blood pressure regulation, and cardiac rhythm, patients and clinicians can better prevent or manage heart disease. Addressing stress, therefore, is not merely about psychological comfort—it is a direct pathway to bolstering cardiovascular resilience and living a healthier, more fulfilled life.

Other related articles

1. O-GlcNAcylation: a pro-survival response to acute stress in the cardiovascular and central nervous systems

The Naked Heart is an educational project owned and operated by Dr Edward Leatham. It comprises a series of blog articles, videos and reels distributed on Tiktok, Youtube and Instagram  aimed to help educate both patients and healthcare professionals about cardiology related issues.

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