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Cause and Signs of Fatigue in the Workplace

11 April 2022

Most people think of fatigue as simply being tired. But fatigue is more than just being tired; it's a lack of energy that can impact your work, health, and mood. Fatigue can have many causes, including stress, sleep deprivation, diet and lifestyle choices, and medical conditions. Knowing the signs and causes of fatigue is essential for managing this condition, so it doesn't interfere with your work or life. In this blog post, we'll explore the causes and signs of fatigue, as well as some consequences you're likely to experience in the workplace. Let's get started!

What is Fatigue?

In recent years, fatigue has become a household word. The term describes an overwhelming sense of exhaustion you get throughout the day. At its simplest, fatigue is characterized by feeling tired and lethargic, physical and mental weariness, and lack of energy. It can be hard to motivate yourself to do anything when you feel this way. It can be caused by physical or mental exertion, illness, poor sleep, or emotional stress.

While short-term fatigue is common and usually resolves on its own, chronic fatigue can signify a serious health problem. Chronic fatigue is defined as a persistent state of feeling abnormally tired for at least six months. Symptoms include difficulty concentrating, memory problems, muscle pain, joint pain, headache, unrefreshing sleep, and post-exertional malaise (a feeling of general ill-health after minimal physical or mental effort).

There are three primary types of fatigue: psychological (mental), emotional (affective), and physical (bodily). Psychological fatigue is a feeling of tiredness or weariness due to stress or anxiety. Emotional fatigue is a state of exhaustion caused by prolonged exposure to difficult emotions such as anger, anxiety, depression, or fear. Physical fatigue is a condition that results from the extreme or sustained muscular effort. It's usually accompanied by muscle weakness.

What are the Causes of Fatigue?

Fatigue can be a major obstacle to productivity in the workplace. It can also lead to health problems if it's not addressed. That's why it's essential to understand the different causes of fatigue. We've outlined some of the most common causes of fatigue:

Irregular Shifts and Circadian (Body Clock) Factors

Irregular Shifts and Circadian (Body Clock) Factors

Irregular shifts and work hours can cause fatigue because they disrupt the body's natural Circadian rhythm. The circadian rhythm is an innate, genetically-driven cycle that regulates the timing of sleep, hunger, activity, and many other physiological processes. It helps to keep our bodies in sync with the 24-hour day-night cycle.

There are a few ways that irregular shifts and circadian (body clock) factors can cause fatigue. One way is by disrupting the body's normal sleep-wake cycle. When our circadian rhythm gets thrown off balance, it can lead to poor sleep quality and insufficient sleep.

Irregular shifts can also influence fatigue by altering the production of certain hormones and neurotransmitters. For example, cortisol - which is responsible for regulating energy levels - peaks in the morning when we're supposed to be most alert and drops off at night when we're supposed to be winding down. Other hormones that are highly correlated with sleep patterns include growth hormones, melatonin, leptin, and ghrelin levels.

Job Stress

There are a few ways that job stress can cause fatigue in the workplace. One way is by causing problems with sleep. When you're stressed, it's common to have trouble falling or staying asleep. This can lead to daytime fatigue and issues with focus and productivity.

Another way job stress can cause fatigue is by triggering the release of the hormone cortisol. Cortisol is a stress hormone that helps your body respond to stressful situations. When released in high levels over long periods, it can lead to physical and emotional exhaustion. It can also lead to problems with concentration, memory, and decision-making.

Bad Posture

When you have bad posture, your body is working harder than it should to maintain balance. This extra work puts stress on your muscles, ligaments, and joints, which can lead to fatigue (your muscles are forced to stay in a shortened or lengthened position that they're not meant to be in).

Bad posture can also cause tension headaches and back and neck pain, which can further contribute to feelings of fatigue. In addition, when you have poor posture, it's much harder for your lungs and heart to circulate blood and oxygen throughout your body. This can lead to feelings of fatigue and general malaise.

Bad posture is relatively easy to correct. Employers need to ensure that the office furniture is ergonomically designed to avert the problems associated with bad posture. Invest in some quality ergonomic office chairs or height adjustable standing desks and begin to enjoy the benefits of reduced muscle aches and, subsequently, less fatigue.

Strenuous Activity

Strenuous Activity

Another common cause of workplace fatigue is strenuous activity at work. This usually develops when people are in physically demanding jobs that require them to regularly exert themselves in heavy lifting activities, such as construction workers who need to lift heavy objects into place throughout the day.


Noise can cause fatigue in the workplace because it makes it difficult to concentrate. When there is a lot of noise, the brain has to work harder to process everything that is going on, which can lead to feelings of fatigue. Loud noise can also create stress responses in your brain, leading to fatigue.

Extreme Temperatures

When the body is subjected to extreme temperatures, it has a harder time maintaining its core temperature, leading to fatigue. If you are in a hot environment, your body will produce sweat in an attempt to cool itself down. Sweating causes fluid loss, and if you lose too much fluid, you may become dehydrated, which can also lead to feelings of fatigue.

Again, the body experiences vasodilation, which is the widening of blood vessels near the skin surface. This response is triggered by the body's need to cool the body by carrying more blood to the skin, which loses more heat to the air. Increased blood flow causes a decrease in blood pressure. And to compensate for this, the heart rate will increase, which can lead to fatigue. Extreme heat can also cause heat stroke and dizziness, which are risk factors for fatigue.

On the other hand, exposure to extreme cold causes body exhaustion when trying to generate enough heat to keep the body warm. Severe cases can cause hypothermia, which is a condition that results in confusion, fatigue, and slowed brain activity.

Medical Sleep Disorder and Underlying Health Issues

Medical Sleep Disorder and Underlying Health Issues

Several medical sleep disorders can cause fatigue, including insomnia, depression, restless legs syndrome, sleep apnea, parasomnias, REM Sleep Behavior Disorder, and narcolepsy. Each of these disorders can disrupt your sleep cycle and leave you feeling exhausted during the day.

Certain underlying health issues can also lead to fatigue, including hypertension, diabetes, thyroid disease, liver disease, epilepsy, anemia, depression, heart disease, autoimmune diseases, such as multiple sclerosis or lupus erythematosus, and cancers, such as leukemia or lymphoma.

These conditions can cause fatigue by taxing the body's resources and limiting the amount of energy that is available for normal functioning. In addition, many of these conditions can also lead to feelings of exhaustion and lack of motivation, which can further contribute to feelings of fatigue.

Coping Substances

Many substances can cause fatigue, including prescription medications, opioids, depressants, alcohol, stimulants, and caffeine. Each of these substances can have different effects on the body and can lead to fatigue in different ways.

Prescription medications can cause fatigue by disrupting the body's natural rhythms or interfering with essential organs' function.
Opioids bind to receptors in the brain and cause slowed breathing, confusion, and drowsiness.
Depressants can inhibit nerve function and reduce energy levels.
Excessive alcohol consumption acts as a sedative that depresses the central nervous system. Alcohol can also disrupt sleep patterns and make users feel tired the next day.
Stimulants stimulate the central nervous system and can lead to an increase in heart rate and blood pressure, leading to feelings of fatigue once the high wears off.
Caffeine is a stimulant that can make people feel alert for short periods of time but can cause fatigue once it wears off. Caffeine also causes jitteriness and agitation.
Drug withdrawal can also lead to fatigue. For example, when someone stops taking an antidepressant medication, they might feel fatigued or sluggish until their brain chemistry adjusts to the absence of the drug.

Poor Diet

A poor diet can lead to fatigue for a few reasons. If someone is not getting the right amount of nutrients, like vitamins and minerals, from their food, then their body will not have what it needs to function properly. Not getting enough protein can also lead to fatigue, as protein is essential for building and repairing muscle tissue. Carbohydrates are energy-giving foods, and a shortage means it denies the body its primary energy source. Furthermore, eating unhealthy foods like processed snacks and sugary drinks can cause blood sugar levels to spike and then crash, leading to feelings of tiredness.


Dehydration can cause fatigue because it leads to a drop in blood pressure, reducing blood flow and reducing the amount of oxygen and nutrients that reach your muscles. Additionally, dehydration can lead to a build-up of waste products in your bloodstream, making you feel tired.

Workers at High Risk of Fatigue

Workers at High Risk of Fatigue

Many workers are at high risk of fatigue, including those who work long hours, night shifts, or rotating shifts. Those who work in transportation, health care, manufacturing, and mining are also at high risk for fatigue. Jobs of the following nature also tend to be at higher risk for fatigue:

Shift workers
Fly-in, fly-out workers (FIFO)
Night workers
Drive-in, drive-out (DIDO)
On-call and call-back workers
Seasonal workers
Emergency service workers

Consequences of Fatigue

Consequences of Fatigue

Below are a few consequences of fatigue in the workplace.

Increased Accidents and Errors

Fatigue affects cognitive performance, including slowed reaction time, decreased vigilance, and reduced working memory capacity. Combining these effects can lead to errors in decision-making and an increase in accidents. Fatigue also affects emotions and can lead to irritability and anger, further leading to poor judgment and accidents.

Impaired Performance and Reduced productivity

Fatigue can reduce performance because it limits the amount of energy available to the worker. This reduced energy impairs cognitive function, slows reaction time, and diminishes strength and dexterity. You may also experience reduced productivity. This is particularly true for jobs that require manual labor or extended periods of concentration, such as driving long distances.

Increased Absenteeism

Workplace fatigue can lead to absenteeism because it can cause chronic fatigue, a severe disorder that may require further medical attention. When someone is chronically fatigued, they are constantly tired and have little energy to do anything. This can lead to people calling in sick or leaving work early because they simply can't handle the day-to-day tasks anymore. Fatigue also makes you more susceptible to developing conditions such as chronic stress, anxiety, and depression.

Finally, when people are tired, their reflexes slow down, and if they work with dangerous equipment, they're more likely to cause workplace accidents leading to injuries and missed days of work while they recover.

Increased Medical Cost

There are many potential causes for increased medical costs and medical conditions, but one possible explanation is that fatigue leads to a general deterioration in health, increasing the likelihood of developing many chronic illnesses. Constant fatigue can also be quite stressful, and stress has been linked with a wide range of health problems.

Reduced Morale and Poorer Labor Relations

Tired workers may be less motivated to do their best work, impacting productivity. This is likely because when employees are overly fatigued, they are less able to cope with stressors on the job, leading to feelings of frustration and anger. These negative emotions can then spill over into relationships at work. Finally, fatigue can lead to feelings of hopelessness and dissatisfaction with one's job, decreasing morale.

Signs of Workplace Fatigue?

What are the Signs of Workplace Fatigue?

There are many signs of workplace fatigue, but some of the most common ones include:

Decreased productivity
Difficulty concentrating
Mood swings
Anger outbursts
Social withdrawal.
Irritability or short temper
Less enthusiasm for work
Lack of Focus
Excessive yawning
Feeling run down or out of energy.
Blurred vision or impaired visual perception
Impaired decision-making and judgment
Reduced hand-eye coordination or slow reflexes
Susceptibility to illness
Allergies, sensitivities, and intolerances


It is essential to take care of yourself at work and outside the workplace. The more we learn about fatigue, the less it seems like an unavoidable part of life. There are many ways to manage your energy levels, not to become overwhelmed or burnt out from working too hard for too long without taking breaks, eating unhealthy food, dealing with stress, and not getting enough sleep. It's also worth noting how this article has touched upon some dire consequences related to increased accidents, errors in judgment, absenteeism, medical costs, and morale/labor relations which may be avoided with a better understanding of the causes of fatigue. We hope that these insights have been helpful and that you're on your way to the healthiest year of your life.