How Stress Affects The Body

Did you know that December is statistically the most stressful time of the year? And did you know that around 86% of UK adults feel stressed at least once a month, and a significant portion of them do absolutely nothing about it? This has to change. 

Stress is a natural part of life, but in today’s world, it can easily become overwhelming. Whether caused by work, relationships, finances, or daily pressures, stress doesn’t just affect how you feel. It has a real, measurable impact on the body.

Short-term stress can actually be helpful, giving you a burst of energy and sharpening your focus. However, long-term stress (sometimes known as chronic stress) can affect everything from your digestion and hormones to your skin, sleep, heart, and immune system.

In this guide, we explore how stress affects the body, how it influences major organs, including the brain and heart, and what long-term stress can do to your health. We’ll also look at how stress affects your period, pregnancy, eyes, and even your face, plus steps to help you regain balance.

What Happens to Your Body When You’re Stressed?

When you’re faced with a stressful situation, the body triggers the fight-or-flight response. This is controlled by the brain’s hypothalamus, which signals the release of hormones like adrenaline and cortisol.

How the Body Responds to Short-Term Stress

Short bursts of stress activate chemical and physical changes designed to help you react quickly. These include:

• Hormone release: Adrenaline and cortisol surge into the bloodstream.
• Increased heart rate and breathing: More oxygen is delivered to the muscles and brain.
• Muscle tension: Muscles tighten as the body prepares for action.
• Energy boost: Glucose is released into the bloodstream to provide fuel.

This response is essential for survival; the body is simply doing what it’s designed to do to survive.

How Chronic Stress Affects the Body

Problems arise when this stress response is switched on constantly; this is commonly known as chronic stress. Chronic stress has long-lasting effects on the body, many of which people don’t always associate with stress at all. Stress affects different parts of the body, in various ways.

How Stress Affects the Brain

Rather unsurprisingly, chronic stress affects both the structure and function of the brain.

Impact on memory and concentration

High cortisol levels can disrupt communication between brain cells, leading to:

• Forgetfulness
• Difficulty concentrating
• “Brain fog”
• Poor decision-making

Effect on mood

Long-term stress is linked with changes in neurotransmitters, which may contribute to:

• Anxiety
• Low mood
• Irritability
• Lack of motivation

How chronic stress affects your brain over time

Long-term exposure to cortisol may reduce the volume of areas like the hippocampus (which is linked to memory), and can impair learning and cognitive function.

How Stress Affects Your Heart and Circulation

When adrenaline rises, your heart beats faster and your blood pressure increases. If this happens occasionally, it isn’t harmful in isolated circumstances. However, chronic stress can contribute to persistently high blood pressure, increased strain on blood vessels, and a higher risk of cardiovascular issues

People under long-term stress often report symptoms such as palpitations, chest tightness, dizziness, or shortness of breath, all of which can worsen when worrying about them.

How Stress Affects Your Digestive System

The gut is one of the most sensitive areas, which means it’s a prime target to be affected by stress. While many of us know about poorly tummies and unusual toilet habits, there are other ways it affects you as well. 

Short-term effects

• Stomach pain
• Nausea
• Butterflies
• Diarrhoea

Long-term digestive effects

Long-term stress can disrupt digestion and gut motility, contributing to:

• Heartburn or acid reflux
• Bloating
• Irritable bowel symptoms
• Changes in appetite (increased or reduced)

Many people also find that stress triggers or worsens intolerance symptoms, particularly bloating and fatigue.

How Stress Affects Your Immune System

Cortisol is designed to reduce inflammation, but if cortisol stays high for too long, it can have the opposite effect.

Chronic stress may lead to weakened immune defences, Increased susceptibility to colds and infections, slower recovery from illness, and the exacerbation of inflammatory conditions. This is one of the reasons people often fall ill shortly after a stressful period. So if you find yourself ill after a particularly stressful period at work or around Christmas time, this could be why. 

How Stress Affects Your Face and Skin

Many of us take great pride in our skin, and a key focus area is our face. The last thing you want is a stress-induced flare-up, which can only further worsen stress and anxiety. Well, stress can show up physically, quite literally, on your face, and it’s a lot more common than you think.

Common skin-related stress symptoms include:

• Breakouts and acne
• Flushed or irritated skin
• Worsening of eczema or psoriasis
• Dark circles from poor sleep
• Premature ageing (stress can accelerate cellular ageing)

Muscle tension from stress can also contribute to jaw tightness, teeth grinding, headaches, or a constantly tense facial expression.

How Stress Affects Your Eyes

If you’ve ever noticed twitching eyelids or blurred vision during stressful periods, you’re not alone.

Stress can affect the eyes through:

• Eye strain
• Twitching (myokymia)
• Blurred vision
• Dry eyes
• Light sensitivity

These symptoms are often linked to cortisol fluctuations, tension, and sleep disruption.

How Stress Affects Your Period

Stress can interfere with the hormonal system that regulates menstruation. When cortisol is consistently high, it can disrupt the release of hormones like FSH and LH, which are essential for ovulation.

Stress may cause:

• Late or irregular periods
• Missed periods (amenorrhoea)
• Heavier or more painful periods
• Worsening PMS symptoms

This is one of the most common, but most overlooked, effects of chronic stress. Stress can commonly delay your period and have other side effects as well. 

How Stress Affects Pregnancy

Stress during pregnancy is very common, and mild to moderate stress is usually not harmful. However, high or prolonged stress can influence:

• Sleep
• Appetite
• Energy levels
• Blood pressure
• Hormone balance

Indirectly, these changes may affect overall pregnancy health. During a pregnancy, the number one priority is the health of you and your baby. If stress is overwhelming, it’s important to speak with a healthcare professional for personalised guidance.

Other Ways Stress Affects Your Health

Stress is more than a feeling; it can create physical symptoms throughout the body.

You may experience:

• Fatigue or exhaustion
• Headaches or migraines
• Muscle aches
• Trouble sleeping
• Low libido
• Mood fluctuations
• Changes in eating habits
• Difficulty focusing

Everyone experiences stress differently, but if symptoms become persistent, it may be time to take action.

How to Support Your Body During Stressful Periods

Managing stress doesn’t mean eliminating it completely; it means helping your body recover from it more effectively. If you are experiencing symptoms brought on by stress, the best thing to do is contact a medical professional for support.

However, if you find yourself experiencing a shorter bout of stress, or you want to try and manage your symptoms at home, there are some proven methods.  Some simple yet effective strategies include:

• Getting regular, good-quality sleep
• Gentle exercise, such as walking or yoga
• Deep breathing or meditation
• Spending time outdoors
• Reducing caffeine or alcohol
• Talking to a therapist or support network
• Identifying and removing avoidable stressors

For some people, underlying food intolerances can make stress symptoms, such as bloating, fatigue, and headaches, feel significantly worse. Understanding how your body reacts to certain foods may help reduce overall stress on the body.

Optimise Your Wellbeing With YorkTest

If you’ve been experiencing symptoms that could be linked to a food intolerance or allergy, our at-home tests offer a simple and reliable way to find answers. YorkTest is the UK’s leading provider of home-to-laboratory food intolerance and allergy testing, backed by expert nutritional support to help you feel your best.

Alongside our food tests, we also offer a wide range of health and wellbeing tests designed to give you clearer insight into how your body functions.

If you’re concerned about your stress levels, whether you’re noticing signs mentioned throughout this blog or simply feel overwhelmed, our stress (cortisol) test can help you better understand what’s happening internally. With personalised aftercare from our expert team, you’ll gain practical guidance to support a healthier, more balanced lifestyle.

Take control of your wellbeing today. Get started with YorkTest.