Daytime Fatigue & Low Energy in Adults: Causes and Treatment Options

How Daytime Fatigue Impacts Mental and Emotional Well-Being

Thinking about how fatigue affects productivity is often a go-to, but what about our well-being outside of our work? Fatigue has an impact on how we think and feel, and moreover, how we socialize and relate to others. In short, it affects all aspects of life.

In fact, research shows that fatigue can impair working memory, slow our decision-making abilities, and make us less emotionally resilient. More simply, fatigue makes us more irritable and sensitive, as well as less likely to engage in activities that we used to enjoy.^[6]

Healthy habits are important – socialising, exercise, and self-care especially – as these lower the risk of issues like depression and anxiety. But, because fatigue makes us less likely to engage in all these healthy activities, pre-existing mental health conditions can be made worse.^[7]

For this reason, understanding the potential causes of fatigue and seeking a professional evaluation when necessary can prevent mental and physical health from declining.^[8] In the following section, we explore the potential causes of excessive daytime tiredness in more depth.

Depression

Depression is a very common mental health condition, and fatigue is one of the core symptoms that clinicians look for when diagnosing it. The daytime sleepiness depression can cause often presents as low motivation, physical exhaustion, and difficulty completing day-to-day tasks.^[9]

Research shows that over 90% of people with depression experience significant fatigue, even when their sleep appears normal.^[10] The reason why largely comes down to chemicals in the brain that regulate mood. Two key players are serotonin and dopamine – these are often described as “mood boosting” or “happy” chemicals. With depression, the regulation of these chemicals is affected. So naturally, mood and energy are changeable and often low in these people with this condition.^[11][12]

Anxiety Disorders

Feelings of anxiety happen when the body is on high alert. The condition is an evolutionary natural response to perceived threats – a state called “fight or flight.” In fight or flight, heart rate and breathing become elevated, priming us to react quickly. Of course, this response was useful for our ancient ancestors in the time of legitimately dangerous threats like predators. But nowadays it can still become activated by everyday stressors, such as work, conflict, and so on.

For people with chronic anxiety, this system is activated repeatedly throughout the day. As a result, cortisol – known as the “stress hormone” – becomes elevated. Over time, this leads to muscle tension, restless nights, and low energy, which goes hand in hand with fatigue. In other words, the low motivation anxiety can cause often initially stems from a state of overwhelm.^[13]

Burnout and Chronic Stress

Fortunately, in a time of greater awareness around work-life balance, burnout is increasingly recognised. It’s a state of emotional and physical exhaustion that’s brought about by prolonged stress, usually in work or in caregiving roles.

Burnout exhaustion symptoms include poor concentration, tiredness that doesn’t get better with rest, and emotional sensitivity.^[14] What’s more, chronic stress leads to elevated release of cortisol (the stress hormone we talked about earlier), which can disrupt the body’s natural sleep-wake cycle. So, if you’re prone to stress long-term, then it’s likely that daytime sleepiness may become an issue.^[15]

Trauma and Post-Traumatic Stress

Post-traumatic stress disorder (PTSD) is as it sounds – a stress condition that occurs as a result of a traumatic experience. Unpleasant triggering memories or environments can lead to emotional responses and states of intense distress in people with this condition.

As a result, many of those affected spend a lot of time in a hyperaroused state, meaning they’re constantly on their guard for threats associated with their past trauma. Sleep can also be disrupted for the same reasons, as symptoms of PTSD include nightmares, insomnia, and being easily startled.^[16] So, the link between trauma and fatigue is quite clear.

Sleep Disorders

Several sleep disorders can cause excessive daytime tiredness. These include:

• Insomnia: This is a difficulty initiating or maintaining sleep, leading to “sleep debt.” Or, to put it more simply, being so underslept that your body craves the hours of sleep you lost to be restored by further rest.^[17] Insomnia is often linked to mental health conditions like anxiety, depression, and PTSD.
• Obstructive sleep apnea: Breathing disruptions during sleep, which cause repeated awakenings during the night, and are often characterized by snoring and reduced oxygen intake.^[18]
• Restless legs syndrome: This is a condition characterized by jerking and twitching of the leg muscles at night. These uncomfortable sensations often disrupt sleep quality.^[19]

As sleep disorders often overlap with mental health conditions, a full evaluation by a healthcare provider can be especially important.

Medical Conditions

If you have a pre-existing medical condition and are noticing symptoms of chronic tiredness, then the two may be linked. Some common conditions that are associated with fatigue include:^[20]

• Thyroid disorders
• Anaemia
• Chronic pain disorders
• Viral infections
• Autoimmune diseases

Alternatively, daytime sleepiness and fatigue may come down to an unrecognized medical issue, which is why it’s always important to get a checkup.

Lifestyle Patterns

Our daily habits can influence how much rest we get and how tired we feel during the day. But, fortunately, if lifestyle factors are a cause, then recovery from fatigue is well within reach by making simple changes in how we go about our day.

For example, if you’re a coffee lover, it may be time to limit your intake or switch to decaf in the late afternoons, as high caffeine consumption is linked to fatigue.^[21] Dehydration is also linked to fatigue, so it’s a good idea to keep a flask of water topped up and within reach when you’re out and about.^[21] Irregular eating habits, like having heavy meals later at night, can also worsen fatigue.^[21]

Cognitive Behavioral Therapy (CBT)

CBT is well researched for depression and anxiety, and studies have shown its effectiveness in improving mood and energy levels.^[23]

With the assistance of a qualified therapist, unhelpful thinking patterns and thoughts are identified. For example, someone who is prone to low mood might make a mistake at work and tell themselves I’m bad at my job. By reframing thought patterns that tend to be negative or presumptuous, someone can achieve more balanced, realistic self-talk, like I made a mistake, I’m only human, and I’ll learn from it.

Medication

For some adults, antidepressant or anti-anxiety medications can help regulate mood and fatigue.

We mentioned the mood-boosting chemical serotonin earlier. SSRIs (selective serotonin reuptake inhibitors) help maintain levels of serotonin in the body. As a result, people often see positive changes in emotional stability and fatigue, especially when depression is present.^[24]

Lifestyle Adjustments

Regular physical activity, consistent sleep-wake schedules, balanced nutrition, and reduced caffeine late in the day can all help to support energy regulation. In fact, moderate exercise, around 30 minutes per day of activity that increases heart rate, has been shown to reduce fatigue and enhance sleep quality, even for those living with depression.^[25]

Therapy for Trauma or Stress

Trauma-focused therapies have shown effectiveness for treating the symptoms of fatigue related to trauma and PTSD.

For example, eye movement desensitisation and reprocessing (EMDR) is a form of trauma-focused therapy that is carried out under the supervision of a qualified healthcare professional. It involves recalling specific traumatic events while a therapist prompts controlled eye movements to aid in emotional processing. This, in turn, can reduce someone’s hyperarousal or sense of being “high alert,” reducing daytime fatigue.^[26]

Further, CBT can also be adapted to process past traumas and promote emotional resilience in the face of triggers and painful memories.