'Tired all the time' is a popular phrase given by patients to their family doctors. Tiredness or fatigue is a common problem. Often, it is not a medical issue but one that can be reversed by a change of lifestyle.
Tiredness can negatively impact performance at work, or have an adverse effect on family life and social relationships.1
Fatigue has a reputation as a vague and difficult problem for doctors to investigate, a 'heart sink' problem, and many people with fatigue do not report it to their doctor.2 Primary care physicians who are conscious of this, and the ongoing patient-physician relationship, will take the problem seriously and attempt to determine an underlying cause.
Contents of this article:
Fast facts on fatigue and tiredness
Here are some key points about fatigue. More detail and supporting information is in the main article.
- Fatigue is also known as tiredness, reduced energy, physical or mental exhaustion, or lack of motivation.
- It is very common and can affect work and social life.
- Causes of fatigue can be psychological, physiological and physical.
- Lifestyle causes include going to bed late, consuming too much caffeine or alcohol, eating junk food and experiencing chronic stress.
- There is a long list of potential medical causes of tiredness, ranging from sleep and breathing problems to liver, kidney and heart disease.
- To diagnose fatigue, a doctor will ask questions and take a sleep history, and may perform a physical examination and blood and urine tests.
- Chronic fatigue syndrome is diagnosed if fatigue is long-lasting, there is no other cause, and certain criteria are met.
- Treatment is focused on the underlying cause of tiredness.
- If there is no medical cause for fatigue, lifestyle changes may solve the problem.
What is fatigue?
Fatigue is more common among women than men.
Simply-put, fatigue is the feeling of being tired. It is generally different from the sleepy feeling of drowsiness, or from the psychological feeling of apathy, although these can both accompany fatigue.3
Other terms to describe fatigue include:1
- Reduced or no energy
- Physical or mental exhaustion
- Lack of motivation.
What causes fatigue?
Fatigue is a common experience - we all feel tired occasionally - but this is not usually due to disease. There are numerous medical and non-medical causes of fatigue, including personal dietary and lifestyle habits.1,2,4
Some groups are more likely than others to suffer from fatigue, with women more often reporting feelings of fatigue. People who live in poverty, and/or who live with mental or physical illness are also more likely to present with fatigue.1
The following is a list of factors that can contribute to fatigue, either alone or in combination, demonstrating just how varied the causes can be:1
Lifestyle factors such as caffeine intake can disrupt sleep and lead to fatigue.
- Psychological and psychosocial - e.g., stress, anxiety and depression
- Physical - e.g., anemia, diabetes, glandular fever, and cancer
- Physiological - e.g., pregnancy, breastfeeding, inadequate rest or sleep, and excessive exercise.
Fatigue that may be considered normal, i.e. not a medical problem, include tiredness as a result of:3
- Physical activity
- Emotional stress
- Lack of sleep.
The National Institute on Aging lists the following lifestyle habits that can lead to tiredness and fatigue:
- Staying up too late
- Having too much caffeine
- Drinking too much alcohol
- Eating junk food.
Snoring could be a sign of a breathing problem that may produce fatigue.
We have touched, above, on a few of the physical causes that can lead to fatigue, along with psychological and physiological factors. The list of physical or medical causes is long, making it important to work with a physician to come to an accurate diagnosis based on an individual's personal and medical history.
The list of potential medical causes of fatigue requiring consideration by a physician includes:2,3,5
- Obstructive sleep apnea
- Sedative and antidepressant treatments
- Iron deficiency
- Kidney disease
- Liver disease
- Heart failure
- Thyroid disease
- Addison disease
- Anorexia nervosa or other eating disorders
- Arthritis, including juvenile rheumatoid arthritis
- Autoimmune diseases such as systemic lupus erythematosus
- Infection, especially long-term
- AIDS, tuberculosis and mononucleosis
Recent developments on causes of fatigue
Poor sleep tied to widespread pain and fibromyalgia. Research in adults over the age of 50 years, published in February 2014, has found a link between poor sleep and fibromyalgia - a condition in which fatigue is accompanied by widespread pain.
How is fatigue diagnosed?
Fatigue is often seen as a difficult issue for doctors to deal with.2 It may be a physical problem rather than a psychological one, and the following conclusion from a research paper about psychological fatigue highlights the need for a partnership to be developed between doctor and patient when working out the problem.6
"Patients consulting for tiredness are likely to report symptoms of psychological distress and attend more frequently than other patients.
"They tend to view the problem as physical while their doctors view the problem as psychological.
"Having established that there is no physical problem, doctors may need to focus more on sharing ideas and explanations when patients complain of being 'tired all the time'."
When working with patients presenting with fatigue, a physician will aim to develop a more precise description of symptoms, typically by asking the following types of questions:1-3
- Have you felt drowsy, or has the fatigue been more a feeling of weakness?
(The answer can give clues to the diagnosis because drowsiness may be a symptom of a sleep disorder, while weakness may be a sign of a neuromuscular cause)
- During the past month have you often been bothered by feeling down, depressed, or hopeless? Or: During the past month have you often been bothered by little interest or pleasure in doing things?
(Positive answers may indicate depression)
- Has your fatigue developed gradually or suddenly?
- Does your tiredness come in cycles?
(For example, depression is indicated if the fatigue is worst in the morning but persists all day, whereas fatigue associated with exercise suggests a neuromuscular issue)
- What are your concerns about the fatigue? What do you think may be the cause?
(The doctor may be looking for a connection with any distressing life events, for example)
Other, more general questions are designed to elicit information regarding any psychological or lifestyle issues, such as feelings of boredom, stress, unhappiness and disappointment. There may be questions about relationships and any recent bereavements or upheavals related to unemployment or housing. The doctor may also ask about a patient's diet and exercise.3
The doctor may take a 'sleep history' to work out whether a sleep disorder is leading to the fatigue:1-3
- How much sleep do you get each night?
- Do you have trouble getting to sleep or do you wake up in the night?
- Has anyone told you that you snore?
- Has anyone noticed that you stop breathing for short periods of time during sleep?
These sleep history questions are designed to determine the sleep quality, quantity, patterns, and sleep hygiene (routine). The history may also reveal snoring, sleep apnea (this is witnessed by someone else noticing you not breathing for a time during sleep), nocturia (the night-time need to urinate), and restless legs syndrome.
The doctor may also examine you physically or check your mental state to help find physical and mental causes of fatigue.5
If no specific cause is indicated for special investigation, there is a set of standard tests used to help narrow down the diagnosis for someone with fatigue. These include:3,5
- Full blood count
- Erythrocyte sedimentation rate or C reactive protein
- Liver function tests
- Urea and electrolytes
- Thyroid stimulating hormone and thyroid function tests
- Creatine kinase
- Urine and blood tests for glucose
- Urine test for protein.
Chronic fatigue syndrome
Any tiredness that persists for a long time can be termed chronic, but medical papers and guidelines set chronic tiredness as being fatigue that lasts at least six months.1
A diagnosis of chronic fatigue syndrome (CFS, also known as myalgic encephalopathy or ME) is made when tiredness persists for more than four months and cannot be explained by another diagnosis.1 Some doctors use six months as the cut-off for considering this diagnosis.2
CFS/ME has specific criteria for diagnosis. In addition to unexplained fatigue with a new or specific onset that has persisted for four months or more, the condition results in substantially lower activity levels and is characterized by malaise and/or fatigue after exertion.1
The person with CFS/ME must also display one or more of the following symptoms:1
- Difficulty with sleeping
- Muscle or joint pain - multi-site without evidence of inflammation
- Painful lymph nodes
- Sore throat
- Cognitive dysfunction (such as difficulty thinking, inability to concentrate, impaired short-term memory)
- Physical or mental exertion makes symptoms worse
- General malaise or flu-like symptoms
- Dizziness or nausea
- Palpitations in the absence of identified heart disease.
A diagnosis of CFS/ME should be reconsidered if none of the following features is present:1
Recent developments in chronic fatigue syndrome
Treatments lead to recovery in chronic fatigue syndrome. In a large UK trial published in January 2013, chronic fatigue syndrome patients who received cognitive behavioral therapy or graded exercise therapy, combined with specialist care, were three times more likely to recover than those on other treatments.
What are the treatment options for fatigue
There is no single treatment for non-CFS/ME fatigue - because the management approach depends on the cause of the tiredness. If there is any general treatment approach, it is to treat the underlying cause.
If the diagnostic process unveils no underlying medical explanation for the fatigue, the following lifestyle and dietary modifications may help resolve fatigue:1,3,7
- Improving your sleep habits and ensuring adequate sleep
- Exercising regularly and balancing rest and activity
- Cutting out caffeine and drinking plenty of water
- Eating healthily to avoid becoming overweight or underweight
- Setting realistic expectations for workload and schedule
- Taking time to relax, perhaps trying meditation or yoga
- Identifying and dealing with stressors by, for example, taking time off work or resolving relationship problems
- Avoiding the use of alcohol, nicotine, and illegal drugs.
For some people with fatigue, who are motivated and psychologically minded, doctors may consider offering a referral for counselling or a talking therapy known as cognitive behavioral therapy.1
Some doctors specialize in chronic fatigue syndrome or ME services, and these may be a suitable referral even for people who do not meet the criteria for this diagnosis. They will offer a consultant opinion for occupational reasons for fatigue, or may provide a structured, multidisciplinary approach to management, including supervised graded exercise therapy.1