What is tiredness or fatigue? How can I beat tiredness?

'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.


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:

  • 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

Woman tired with coffee in her hand
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
  • Boredom
  • 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.