Fatigue is one of the most debilitating aspects of living with a brain injury.

Although everyone experiences it differently, fatigue has a negative impact on every part of daily living and makes it hard for you to take care of yourself well, which often exacerbates the problems you have. 

It can feel like a vicious circle where there is no let up and no reprieve.

Pathological fatigue doesn’t go away after resting or taking a nap. The severity with which it is felt is greater and it can last for long periods of time becoming a chronic problem.

You might notice that your fatigue affects your moods. how you relate to other people, getting things done or doing things you would usually have enjoyed, and even how you feel about yourself. Chronic fatigue can have many knock-on effects and is extremely hard to manage.

Unless you address the root causes of chronic fatigue, it might continue to affect your quality of life, and your ability to rehabilitate.

Getting to the nitty-gritty and making the needed changes is crucial. Hopefully we will help you do that.

  • Introduction
  • Causes
  • Fatigue and the Adrenals
  • Understanding fatigue
  • Managing Fatigue
  • References


Research shows that over 70% of people report fatigue following brain injury. 

While many doctors and researchers feel that symptoms should clear up between a few days and three weeks for concussion, and between two months and a year for ‘mild’ traumatic brain injury (mTBI), the lived experience often differs greatly from these expectations.  It is known that symptoms generally persist for long periods in moderate and severe injuries, and stroke/neurosurgical patients.

When it comes to the realities, many people talk about fatigue, including people diagnosed with concussion and mTBI, as persisting for a long time. We asked 98 people diagnosed with mTBI how strongly fatigue affected them.

Of the 46 people diagnosed more than four years ago, 48% reported that they still struggle all the time with fatigue, and 40% said that they are affected almost all the time.

The other 12% in this group reported that fatigue remains problematic about 50% of the time.

Although this was a small study, the numbers show that the realities are indicative of the need for more detailed research.

Pathological fatigue, caused by biological malfunction, is often very debilitating, challenging to manage, and can have a significant impact on many areas of peoples lives.

Unlike normal tiredness, pathological fatigue is unalleviated by rest.


The leading causes of prolonged fatigue are the unaddressed inflammatory effect of the biochemical cascade that follows immediately after the ‘primary injury,’ the resultant adrenal fatigue, and rapid depletion of vitamin and mineral reserves. 

A lack of quality nutrients in the diet in the very early stages exacerbates these problems, as does a poor diet over the longer term.

Many other factors can affect fatigue, such as the age, health, diet, environment, level of education and the kind of lifestyle a person was leading at the time the brain injury happened.

The glymphatic system in the brain. Image credit: University of Rochester Medical Center

The glymphatic system in the brain. Image credit: University of Rochester Medical Center – click for link

Physiologically many of the causes of fatigue result directly from the injury itself. Many changes contribute to fatigue such as the loss of/disturbance to neuronal connections and changes to neurotransmitters/hormones. As a result, the neural environment becomes toxic, and this can overburden the ‘glymphatic’ system slowing the clearance of waste products from the brain.

This overload adds to the prolongment of symptoms for people across the entire brain injury spectrum, exacerbating executive problems with slowed processing, maintaining attention and emotional/behavioural changes. A toxic brain environment increases feelings of lethargy, brain fog, and decreases motivation.

The ascending reticular activating system (ARAS) influences the amount of information that the thalamus relays to conscious awareness and maintains alertness. Problems with how this system works after a brain injury, also plays a role in apathy.  Research indicates these systems, linked to the brainstem, also play a role in pathological fatigue.

Research shows that the brain works harder and uses more energy to process information following a brain injury. Neuro-fatigue impacts everything someone living with a brain injury does, and can impact social activities and contribute to isolation.

PET scans show that more areas of the brain are involved in performing routine activities than before the brain injury using more energy and slowing processing. Many people feel drained by the extra effort and work needed to perform simple tasks and find it difficult to do more than two hours of activity per day.

Fatigue symptoms can be more severe where there is a concurrence of depression, anxiety, and stress, all of which can cause sleep problems and low mood, adding to the feeling of being desperately tired. Other contributing factors are pain, and the mental and psychological effort it takes for people to adjust to traumatic change.

Sleep problems also increase the prevalence of fatigue because it is during phases of deep restorative sleep that the glymphatic system eliminates toxins and waste, and healing mechanisms are activated. Vitamin D plays a crucial role in sleep, and research shows that reserves can be depleted by as much as 50% in the first 24 hours after a brain injury.

There is often a failure for doctors to perform blood tests at any time post-injury adding to feelings of helplessness, and the burden of loss of control people struggle with. There can be a tendency for doctors to look to pharmacological solutions to symptoms, and for these to be dealt with individually rather than holistically. Furthermore, many doctors don’t consider the healing power of micronutrients or consider depletions as an explanation or causal to symptoms.

Some of the medications prescribed post-injury can also contribute to fatigue.

Fatigue and the adrenals

The biochemical cascade that occurs immediately following a brain injury causes the adrenals to continuously fire due to the biological perception of stress and psychosomatic indicators. 

The adrenals become over-taxed and begin excreting so many stress hormones that the body begins to shut down, causing feelings of exhaustion. The on-switch causing this constant firing creates a feedback loop in the body associated with the fight or flight response, which is also why PTSD and anxiety symptoms can continue unabated for years.


The adrenals are responsible for keeping cortisol and adrenaline in check as well as regulating inflammation in the body. This constant firing damages adrenal function, and many people become deficient in average levels of cortisol, again exacerbating feelings of fatigue.

The continuance of these inflammatory responses, and the more damage the kidney meridian experiences, the more our vital energy is depleted. In turn, this then causes even more problems such as issues with the brain managing pain signals, and also problems with hearing and hearing loss, and the development of food allergies. The later is also linked to changes in immune functionality.

Fatigue following brain injury is also really well explained by traditional Chinese medicine (TCM). In TCM, kidney meridian health determines not only your vital life force (Qi energy) but also defends against chronic illness and the effects of ageing. Your kidney meridian stores ‘essential Qi,’ fuelling mitochondria health, cell renewal and metabolism – the process of turning nutrients into fuel or energy.

In TCM the kidneys and adrenals are seen as a single organ or energy centre. Science is helping us understand the source and flow of energy in accordance with eastern traditions dating back many thousands of years.

When the adrenals start to struggle, they no longer manufacture the right balance of hormones, and initially release too much cortisol and adrenalin into the body.

To start with, tired adrenals cause people to feel wired and tired, so although healthy adrenals usually fire more in the morning, when they are fatigued, they will instead fire at night. This late release of hormones leads to insomnia and problems with getting the brain to be quiet when you go to bed.

Unaddressed, adrenal tiredness can cause adrenal exhaustion. Following a brain injury, the body is full of cortisol much more often because of the effects of the biochemical cascade. As above, this output can result in a boost of energy at night when you don’t need it, and leaves people feeling sluggish and foggy-brained during the day.

People can not only have problems with getting to sleep but can also struggle with going back to sleep if they wake up during the night.

Adrenal exhaustion is a recognised second stage before reaching full adrenal burnout. Staying in a state of high-cortisol eventually leads to cortisol levels starting to fail. Associated problems include weight gain, increased sleep problems, and a recognition that something is affecting general health.

Full adrenal burnout leaves people feeling drained and burned out. By this time, there are disruptions to cortisol patterns, and background levels of cortisol are way below average. Low levels of cortisol production are associated with a higher risk of thyroid and autoimmune disease, and are also known to cause problems with the microbiome and absorption of nutrients.

This vicious circle can also exacerbate symptoms of anxiety leading to panic attacks so when people notice an escalation in their symptoms these are very often associated with the depletions in vitamin B6 and iron caused by cortisol overload.

B vitamins, in general, are associated with better mental health, and can help to minimise the risks of fatigue, anxiety, irritability, emotional instability, and even agoraphobia if people supplement with a multi-complex range of B vitamins in the early stages following a brain injury. This strategy will also help to reduce symptoms at any stage following a brain injury.

Avoid self-diagnosis and paying for information on the internet. Your doctor, dietician/qualified nutritional expert or naturopath, will be able to tell you all you need to know about vitamins and minerals.

Understanding fatigue

Feeling extremely weary all the time can reduce peoples’ motivation, and often causes problems with being able to undertake any activity.

Lethargy, apathy, inactivity, and difficulties getting started, can be especially problematic for people who have families to care for, and for people who are working.

Feeling like a burden, a loss of independence, and being unable to contribute to regular responsibilities, can add to feelings of frustration, stress and anxiety. In effect, the impact of the outcomes and symptoms of fatigue, can create a self-perpetuating negative circle.

When levels of activity are reduced by fatigue, this can also bring about feelings of boredom, which, in turn, can increase feelings of irritability.

In many ways, each outcome and symptom can create a domino effect. For example, being unable to process and filter incoming information can not only induce feelings of being overwhelmed but can lead to frustration and emotional outbursts adding further toxic chemicals to the brain environment. Negative emotional responses to non-characteristic behaviours, such as embarrassment or sadness, can also make things even worse.

It isn’t only the fatigue that is debilitating for people – the whole ripple effect and sequence of resultant events can add to the chain reaction. Sometimes it is difficult for people to notice those activities which trigger fatigue because of problems with awareness and self-feedback, and also because fatigue can seriously affect thinking and alertness causing brain-fog.

Neuro-fatigue is quite unlike being tired because you have burnt the candles at both ends. Many people struggle with ‘crashing,’ for example; someone could be getting ready to go out in the morning, sit down to put a shoe on, and wake hours later, still sat in the same place – with one shoe on.

In many ways, it is a bit like a lithium battery that hasn’t been well treated – energy can drain rapidly even when people are minimising activities. Even in ‘quiet mode’ the brain uses enormous amounts of energy, and activities like chatting to friends or watching tv, can also leave a person exhausted. There are no comparisons between everyday tiredness and neuro-fatigue.

Managing fatigue

People manage their fatigue in many different ways. For example, they may try to undertake tasks in the mornings when they have more energy, or may learn when to take breaks or to take a nap.

Dr Raymond N. Perrin DO PhD, Registered Osteopath and Neuroscientist, advocates that laying down for thirty minutes during the day can promote the functioning of the glymphatic system, and may be part of the reason why people feel refreshed after a short nap.

As above, there are links between feeling more able to manage tasks in the morning, and the natural cycles of the production of cortisol. In many people, adrenal deficiency leaves them with lowered basal levels of this hormone, so many people can struggle to get up at all.

To reiterate, living with brain injury outcomes can be incredibly stressful, and periods when people are in fight or flight mode increase for many reasons post-injury, including for those who struggle with anxiety and PTSD. Your body makes cortisol to help you deal with the stress, and while this response is vital, it’s also crucial that cortisol levels return to normal as soon as possible. For many people post brain injury, these levels eventually start to return to lower than normal levels.

For some people, the stress response is activated so many times during the day that the body has no time to recover – resulting in people feeling depleted and unable to function.

Post brain injury, the body can become pre-occupied with manufacturing cortisol. This over-production depletes reserves needed for making other essential hormones and neurotransmitters like aldosterone, testosterone and epinephrine. In turn, these other hormones are necessary for keeping stress under control, and, again, you end up in the vicious circle.

While taking a nap or trying to manage prioritised tasks in the morning are amongst many of the coping strategies suggested for managing fatigue,  they often don’t help very much in improving daily life management or social and leisure activities, which many people can miss a great deal.

One of the best ways to improve fatigue is to tackle the causes at their root, which means addressing the cascade of biochemical changes that occurs after injury and supporting your adrenals.

The best supplements that help with this are:

  • a high-grade quality omega 3 fish oil
  • blessed black seed oil
  • turmeric
  • good quality pro-biotic

Other supplements may also be of benefit. Your doctor will recommend any vitamin or mineral supplements necessary to boost deficiencies.

Eating for nutrition is imperative for many reasons, and helps us to tackle the causes of fatigue, and many of the other common symptoms at their root.

Incorporating a whole-body approach and considering all bodily systems can bring the body back to health. The cascade of adverse chemicals can deplete good gut flora which in turn impacts the immune system and, as discussed above, can cause adrenal fatigue compounding the problems faced. Furthermore, a brain injury is known to have a ‘significant’ impact on gut health.

You can learn more about all of these, including alternative treatments, in ‘Positive Health.’

You can make real changes yourself, and depending on whether you have other health problems, the length of time your fatigue has been going on and other factors, you may see results fairly quickly.

NCBI – Traumatic brain injury and adrenal insufficiency: morning cortisol and cosyntropin stimulation tests

NCBI – The Glymphatic System – A Beginner’s Guide

Acta Medica Okyama – Low Serum Concentrations of Vitamin B6 and Iron Are Related  to Panic Attack and Hyperventilation Attack

Science Direct – Information processing following mild head injury

Science Direct – Reticular Activating System