Understanding Stress: What It Does to Your Body and How to Regain Control
Discover what happens to your body during stress, how chronic stress affects your health, and practical steps to regain calm through planning, movement, and better daily habits.
Did you know 3 in 4 UK adults experienced overwhelming stress at some point over the past year? We might not realise, but we are all stressed (to different levels).
Remember the deadlines, kids screaming because they want ice cream, and the bills you have to pay by the end of the month. In fact, stress is a part of our daily lives.
Stress has been with us since time immemorial.
During the hunter-gatherer era, humans struggled for food, water, and shelter. Now, we have a roof over the head and food on the table, and yet we are stressed.
What Is Stress?
Stress is actually a survival mechanism that allows us to respond quickly to perceived (or real) threats or demands. Short bursts of stress, also known as acute stress, can be beneficial. As the Yerkes-Dodson law says, optimal arousal related to stress can help improve performance and focus. (1)
However, stress past a certain level can backfire, making us anxious and less able to perform a task. Prolonged stress has been associated with many physical and psychological conditions, which we will discuss later.
The Biology of Stress: What Happens When We Are Stressed?
Our stress response involves a series of steps, both in the brain and body.
When our brain perceives a situation as a threat or challenge, the part of the brain that processes fear and anxiety sends distress signals to the command centre of our brain. We call it the hypothalamus.
The hypothalamus responds to messages from the brain and body to keep us safe and stable. It does so through what we call the autonomic nervous system (ANS). The ANS regulates involuntary body functions as breathing, blood pressure, and heartbeat.
There are two components of the ANS:
- Sympathetic nervous system: Promotes the fight-or-flight response
- Parasympathetic nervous system: Promotes the rest-and-digest response
Now, let’s get back to the distress signal.
After the hypothalamus receives the signals, it activates the sympathetic nervous system, which activates the adrenal glands on the top of the kidneys. These glands produce and release hormones called adrenaline (epinephrine) and cortisol into the bloodstream, leading to increased:
- Heart rate
- Blood pressure
- Breathing rate
- Pulse rate
- Blood sugar levels
- Inflammation
Also Read: Chronic Inflammation Is Widespread In the UK. Here’s What You Can Do to Keep It At Bay
In the meantime, digestion and other processes pause or slow down so that more energy becomes available to cope with the threat.
All these changes, which happen instantly, keep our brain alert. When the brain perceives that the danger has passed, it activates the parasympathetic nervous system, which calms down the body.
Causes of Chronic Stress
Chronic stress often stems from financial issues, strained relationships, poor health, health challenges, and a dissatisfying job.
Types of Stress Response
There are three types of stress response: (2)
1. Positive
This is our body’s response to mild stressors, such as a tough test at school. It is typically short-lived and can help us perform better. The body’s pre-stress state recovers quickly on its own.
2. Tolerable
This is our body’s response to temporary stressors, such as moving or a change of job. It prepares our body to adapt to a new environment. The body’s pre-stress state recovers within days or weeks without any long-lasting effects.
3. Toxic
This is our body’s harmful response to intense or long-term stressors. It is when our body is constantly under elevated stress response over prolonged periods.
What Are the Early Signs of Stress?
The early signs of toxic stress can include inconsistent performance, overworking, or a lack of motivation. We may also notice aggressive behaviours, limited social interaction, or bullying. Physical signs can include excessive sweating, headaches, and nervous speech.
Over time, a person may engage in heavy drinking, smoking, and risky behaviours. (3)
What Are the Long-Term Effects of Stress?
Untreated long-term stress affects all organ systems of the body. In the upcoming section, we will learn about the effects specific to the bodily system.
Musculoskeletal system
Acute stress causes our muscles to become tense. Fortunately, our muscle tone restores once the stress passes. However, chronic stress keeps our muscles tensed almost every time, which can lead to headaches, neck pain, and back pain.
Respiratory system
Stress is unlikely to affect people with no pre-existing respiratory problems, except for temporary rapid breathing. However, chronic stress can worsen symptoms in those with asthma or chronic obstructive pulmonary disease (COPD).
Cardiovascular system
Chronic stress can damage blood vessel linings and increase the risk of high blood pressure, heart attack, or stroke. Besides, being chronically stressed may also affect cholesterol levels, and hence heart disease risk.
Immune system
Short-term stress can boost our immune system. Contrarily, long-term stress can weaken our immune response by decreasing the levels of infection-fighting white blood cells called lymphocytes.
Besides, anxiety and depression associated with chronic stress may increase inflammation. Chronically elevated inflammation is a sign that our immune system is overworked and is less efficient at protecting us from diseases and infections.
Effects on sleep
Some people are extremely sensitive to the effect of stress on sleep. In those people, even a moderate level of stress can significantly affect sleep quality. They are also more likely to develop mental disorders like depression and anxiety, both of which are independently linked to chronic stress.
Effects on fertility
Long-term stress can affect fertility in both men and women.
It may cause lower sperm quality in men, most likely associated with increased oxidative stress and low testosterone levels. Higher stress levels may raise the risk of infertility in women.
Everyday Ways to Regain Control
Stress is widespread, but thankfully, simple consistent lifestyle changes can help keep stress levels in check.
Stay Active
Exercise is a natural stress reliever.
When we exercise, our brain releases feel-good hormones called endorphins. These substances help increase feelings of happiness and reduce feelings of pain. Any activity that increases your heart rate (aerobic exercises) can make you feel happier.
Exercise helps lower resting heart rate, strengthens the immune system, and reduces blood pressure. All these can protect against the harmful effects of chronic stress.
According to the NHS, adults should exercise for at least 150 minutes (moderate intensity) or 75 minutes (vigorous intensity activity) each week. To get the weekly dosage of physical activity, it’s best to start with brisk walking, water aerobics, dancing, or hiking.
Get outside daily
Spending time in nature is another great way to reduce stress. Doing so helps us connect with nature and get sunlight. Sun exposure, particularly within minutes of waking up, has been shown to regulate our body’s internal clock, the circadian rhythm. (4)
Besides, UV rays from sunlight help our skin produce vitamin D. Our body needs vitamin D to make hormones that regulate sleep, mood, and overall quality of life.
To get the optimal benefits, we should aim to spend at least 120 minutes each week in nature. For adequate vitamin D levels, we should get about 15 minutes of midday sunlight daily with two-thirds of our skin directly exposed to sunlight.
Also Read: How Low Vitamin D Levels Impair Your Immune Health
Plan your day
Setting a daily routine in advance gives us a sense of control and helps reduce uncertainty. A simple and realistic to-do list can save us from daily hassles.
We may also write down our feelings, emotions, potential stress triggers, and experiences in a diary. This practice, called journaling, can help reduce stress and improve feelings of well-being. Recognising the triggers will help us avoid them or develop coping skills. (5)
Why not start writing 4 to 5 lines each day?
Digital boundaries
Our phone shouldn’t be the last thing we see before we fall asleep.
Excessive screen time, especially near bedtime, can lead to poor sleep quality, which can increase daytime stress levels. Reducing daily screen time and avoiding phone at least an hour before sleep can improve sleep quality, self-control, and self-regulation. (6)
Sleep well
There’s a two-way relationship between sleep and stress. Poor sleep can increase stress levels, and stress can make it difficult for us to get enough quality sleep.
Studies have shown that our stress level drops when we get enough sleep. (7) We should aim to get 7 to 9 hours of sleep each night. Apart from the sleep duration, it’s also critical to have consistent sleep and wake times.
If stress is causing sleep problems, the following tips can help:
- Practicing relaxation techniques like deep breathing or meditation before bedtime.
- Taking a shower.
- Avoiding sleep disruptors like coffee, alcohol, nicotine, and large meals hours before going to sleep.
- Drinking herbal teas.
We can also use a SLEEP CALCULATOR to determine the optimal sleep schedule.
Pause and breathe
In moments of intense stress, a deep breath helps re-engage rational thinking. Besides, deep breathing, with exhales longer than inhales, helps activate the brain’s “rest-and-digest” response. This response calms the body down by reducing the blood pressure, heart rate, and stress levels.
Simply put, deep breathing acts as a switch that turns off the body’s “fight-or-flight” response and turns on the “rest-and-digest” response.
Click HERE to learn more about the calming breathing techniques from the NHS website.
How Food and Alcohol Affect Stress
The relationship between food, alcohol, and stress is more nuanced than what we might think.
What we currently know is higher consumption of ultraprocessed foods and alcohol is associated with an increased risk of mental health issues. (8)
But we still don’t fully understand the underlying mechanisms. We also don’t know whether a bad diet actually increases stress, or whether we simply eat more unhealthy foods (and drinks) when we’re stressed. It could work both ways.
A bad diet may elevate perceived stress levels by causing sugar spikes and crashes. Similarly, drinking alcohol, which can feel relaxing initially, can make us more sensitive to stressors. Remember “hangxiety”, a combination of stress and guilt, after a night of heavy drinking.
Over time, heavy alcohol use can chronically disrupt sleep and raise cortisol levels. (9)
Further Reading: How Alcohol Affects Your Metabolism and What You Can Do
The solution: The basics of a healthy diet remain the same. Eat whole grains, fruits, vegetables, lean proteins, and healthy fats. Limit ultraprocessed foods and red meat. Also, make sure you stay hydrated throughout the day.
Further Reading: Why Leafy and Green Vegetables Should Be on Every Plate
If you choose to drink, drink within the recommended limits.
When to Seek Help
Stress is ubiquitous and natural, but we should never ignore chronic stress.
If you or anyone you love is struggling with persistent overwhelming stress, talk to a GP, mental health professional or counsellor.
Note: This article offers general information, not medical advice. Emotional stress is complex and personal. While Clinic Nutrition doesn’t provide counselling, general principles like acceptance, gratitude, and focusing on the positive can reduce emotional tension.
References:
- Simply Psychology. “Yerkes-Dodson Law of Arousal and Performance.” Simply Psychology, 14 Aug. 2025, www.simplypsychology.org/what-is-the-yerkes-dodson-law.html.
- National Academies of Science, Engineering, and Medicine. The Biology of Toxic Stress. osg.ca.gov/wp-content/uploads/sites/266/2020/12/Part-I-3.-The-Biology-of-Toxic-Stress.pdf.
- Employers, Nhs. “Supporting Our NHS People Experiencing Stress.” NHS Employers, 27 Mar. 2025, www.nhsemployers.org/articles/supporting-our-nhs-people-experiencing-stress#.
- Singh, Anurag Kumar, et al. “The Effects of Vitamin D Levels on Physical, Mental Health, and Sleep Quality in Adults: A Comprehensive Investigation.” Frontiers in Nutrition, vol. 11, Nov. 2024, p. 1451037, doi:10.3389/fnut.2024.1451037.
- Content – Health Encyclopedia – University of Rochester Medical Center. www.urmc.rochester.edu/encyclopedia/content?ContentTypeID=1&ContentID=4552.
- Setia, Sajita, et al. “Digital Detox Strategies and Mental Health: A Comprehensive Scoping Review of Why, Where, and How.” Cureus, vol. 17, no. 1, Jan. 2025, p. e78250, doi:10.7759/cureus.78250.
- American Psychological Association. “Stress and Sleep.” American Psychological Association, 2013, https://www.apa.org/news/press/releases/stress/2013/sleep
- Sazali, Azira, et al. “Higher Ultra-Processed Food Consumption is Associated with Increased Risk of Mental Health Issues in Undergraduates.” Jurnal Gizi dan Pangan, vol. 20, no. 1, 2025, pp. 51-60. Jurnal Gizi dan Pangan, https://journal.ipb.ac.id/index.php/jgizipangan/article/view/61725
- Badrick, Ellena et al. “The relationship between alcohol consumption and cortisol secretion in an aging cohort.” The Journal of clinical endocrinology and metabolism vol. 93,3 (2008): 750-7. doi:10.1210/jc.2007-0737
