Dr. Martina Melzer, published: 01/22/2022, updated: 01/20/2023


What is Fatigue?

Defining fatigue is not that easy. Fatigue comes from the Latin word fatigatio, which means fatigue or tiredness. A person who experiences fatigue usually speaks of a pronounced exhaustion, a state of weakness that does not improve with rest and sleep. Fatigue affects not only physically, but also mentally and emotionally. It clearly limits one in everyday life. It can prevent one from starting an activity and one feels exhausted by an activity very quickly.

Fatigue is a symptom that can have many causes. Doctors often speak of fatigue syndrome because this condition can be described by many individual symptoms. For example: extreme tiredness, problems concentrating and remembering things, slower reaction times, physical weakness, depressed mood, sleepiness.

Fatigue can be acute and chronic.


Tired or fatigued?

If a person talks about being exhausted, he or she often gets the answer "Oh yes, I'm tired all the time too". From my point of view, there is a fundamental difference between tiredness and exhaustion. One is tired after a bad night, after a long day at work or after sports. That is normal. Then you rest and feel fit again, you have strength, you can think clearly, you can go about your daily activities. Not so with a person who suffers from exhaustion. He or she feels permanently like "battery empty", every small everyday activity represents an extreme feat of strength, you feel totally drained, like a zombie. And the battery simply cannot be fully recharged, no matter how much rest and sleep one allows oneself.


What can trigger exhaustion?

Numerous diseases can cause this persistent state of exhaustion. Among them:

  • ME/CFS
  • Cancer
  • Anemia
  • Thyroid diseases
  • Liver diseases
  • Infections
  • Rheumatism
  • Fibromyalgia
  • Multiple Sclerosis
  • Depression
  • Anxiety
  • Sleep apnea
  • Cardiovascular diseases
  • Chronic inflammatory bowel disease (IBD)
  • Irritable bowel syndrome
  • POTS (Postural Tachycardia Syndrome)
  • Parkinson's disease
  • Stroke
  • Burnout, Adrenal insufficiency
  • Celiac disease
  • Persistent sleep disorders
  • (complex) Posttraumatic stress disorder (PTSD)
  • Highly Sensitive Personality (HSP)
  • Long Covid

Medications can also lead to fatigue.


Fatigue: A protective mechanism?

Scientists have not yet found out exactly what happens in the body during exhaustion. But there is much evidence to suggest that the immune system plays a role. Everyone knows the exhaustion of having a cold or flu. The infection activates the immune system, which triggers inflammation to fight the pathogen. Inflammatory chemicals in the brain make us tired, "mushy", exhaust us, we are in a bad mood, we want to lie down and have our rest. This behavior, which makes sense to the body, is called "sickness behavior". It probably plays a role whenever there is inflammation in the body.

Second, the autonomic nervous system has an impact on fatigue, especially when it is out of balance. Again, the nervous system can ramp up a protective mechanism if it has been overstimulated for too long. It then forces the body into a so-called "shutdown".


What is ME/CFS?

ME/CFS means: Myalgic Encephalomyelitis and Chronic Fatigue Syndrome. Some people use the term „chronic fatigue“. US-scientists have proposed to name the disease Systemic Exertion Intolerance Disease (SEID).

Because many patient organizations prefer the name ME/CFS, I use it too. According to the World Health Organisation (WHO) ME/CFS is a neurological disease, which means it affects the nervous system. It is not a psychological illness.


Possible Triggers

In many cases ME/CFS begins with an infection, for example with the Epstein-Barr-virus, the flu, corona- or enteroviruses. Certain bacteria and other pathogens can lead to the illness as well.

Sometimes an accident or a surgery led to the onset of the illness, one is exposed to toxins and in other cases there is no clear special event and ME/CFS starts more subtle.

Stress is an important trigger.


What could be the root cause?


It is still not clear what causes ME/CFS. But scientists find more and more abnormalities, which could play a role in the pathomechanism of the illness. This includes abnormalities in the immune system, the hormonal system, the cardiovascular system, the autonomic nervous system, the energy metabolism and the gut. Genetics increase the risk of getting ME/CFS.

Typical symptoms

These 3 main symptoms are required:


  • Not being able to participate in routine acitivities that were possible before becoming ill, this is accompanied by a profound fatigue, the condition lasts for more than 6 months
  • Post-exertional malaise (PEM)
  • Unrefreshening sleep

In addition you must have cognitive problems, such as impaired memory and „brainfog“ or orthostatic intolerance, which means you get certain symptoms when standing upright.


The long way to the diagnosis

Many affected people, including myself, have been through a doctor´s odyssey for years until they get the diagnosis ME/CFS. One reason is, that many physicians are not well informed about this illness. The current media attention on Long Covid will hopefully change that. Another reason is: The symptoms are not specific (except of the PEM) and can be evoked by many other illnesses too. This often means, that many other conditions have to be ruled out. Are other diseases excluded, fit the symptoms and the history of the patient, then an expert can make the diagnosis ME/CFS.


And then?

Then you finally got the diagnosis and – at the latest – start googling. Unless your physician has already told you, you learn quickly what Pacing is and why it is so important when having ME/CFS. Pacing means as much as: Know your energy envelope and stay within it, as best as you can. Even for mild affected people this can be terribly restrictive and can mean sitting most of the day, giving up your job, deciding whether to take a shower or clean the dishes at that day. More severely affected people are often bedbound and need care.

Besides Pacing a lot of people try to help themselves with countless supplements which shall improve the energy metabolism. Some have to take painkillers, sleeping pills or certain low-dose antidepressants (against pain).

Currently there is no scientifically based therapy.


Recovery is possible!

There is a highly conflicting debate about whether it is possible to fully recover from ME/CFS. There are few studies and reviews that have addressed the issue. One review shows: Within three years, 4.5 to 83 percent of children and adolescents with ME/CFS have recovered. Another analysis showed: on average, five percent of those with the disease recovered completely and 39.5 percent improved their condition. A long-term study of children and adolescents showed that 68 percent had recovered within 10 years.

One of the reasons that the results differ so widely is that the studies were not done uniformly and there were different criteria for when someone was considered recovered. In addition, there are no markers that can be used to say: Blood test back to normal, person healthy. Rather, it is a very personal definition and assessment.


Yet you find more and more people on the internet who have recoverd from ME/CFS and share their story.


Translated with the help of DeepL


PS: Of course, I research and check everything I write here as well as possible. Nevertheless, I am only human and make mistakes. In addition, I may draw completely different conclusions as someone else would. Simply because they fit my story. But every story is different.


Important: The content on this page is for informational purposes only and is not a substitute for talking to your doctor or other therapist. The content reflects my personal experiences, research and findings that have helped me and that I therefore want to share. However, in your personal case, completely different things may play a role and other things may help. Please talk to your doctor or therapist before making any decisions that affect your physical or mental health. Also important: I don't want to convince anyone of anything here. Rather, I want to point out possible ways that hopefully can help some people to improve or overcome their ME/CFS or other syndromes.


Institute of Medicine (IOM): Beyond ME/CFS – A guide for clinicians, 2015

MRI Chronisches Fatigue Centrum München: https://www.muenchen-klinik.de/krankenhaus/schwabing/kinderkliniken/kinderheilkunde-jugendmedizin/spezialgebiete-kinder-klinik/chronische-fatigue/

US ME/CFS Clinician Coalition: Guideline for the Diagnosis and Treatment of ME/CFS, 2019

Centers for Disease Control and Prevention (CDC): Myalgic encephalomyelitis. https://www.cdc.gov/me-cfs/about/index.html


Moore Y et al: Recovering from Chronic Fatigue Syndrome: A systematic review. Arch Dis Child 2021

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Rowe KS: Long term follow up of young people with CFS attending a pediatric outpatient service. Front Pediatr 2019


Deutsche Fatigue Gesellschaft: Was ist Fatigue? Online: https://deutsche-fatigue-gesellschaft.de/fatigue/was-ist-fatigue/


Health direct: Fatigue. Online: https://www.healthdirect.gov.au/fatigue


Pschyrembel Online: https://www.pschyrembel.de/fatigue/K0R64/doc/


Charité Fatigue-Centrum: https://cfc.charite.de/fuer_aerzte/veroeffentlichungen/


Christian Schubert: Was uns krank macht, was uns heilt. Korrektur Verlag 2021