Fatigue can result from a mental or physical health condition, medication use, or chronic pain, among other reasons. Treatment involves managing the underlying cause.

Physical and mental fatigue are different, but they often occur together. Repeated physical exhaustion can lead to mental fatigue over time.

Poor sleep, particularly when it occurs for a long time, can also lead to fatigue. Officials recommend that adults get 7–8 hours of sleep each night. According to some research, however, around 1 in 3 people in the United States say that they do not get enough sleep.

Eating a healthful diet and getting regular physical activity can help reduce fatigue for many people. Treating the underlying cause of fatigue, whether this is poor sleep or a health condition, also helps.

When fatigue affects safety, it becomes a public health concern. People with severe fatigue may act similarly to those who are intoxicated.

This article will look at the types of fatigue, some causes, and the treatment options available.

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There are two main types of fatigue: physical and mental.

A person with physical fatigue may find it physically hard to do the things they usually do, such as climbing the stairs. Symptoms include muscle weakness, and diagnosis may involve completing a strength test.

With mental fatigue, a person may find it harder to concentrate on things and stay focused. They may feel sleepy or have difficulty staying awake while working.

Sleepiness can occur when a person does not get enough good quality sleep, or when they have a lack of stimulation. It can also be a symptom of a health condition that interferes with sleep, such as sleep apnea or restless legs syndrome.

Sleepiness is more likely to be short-term than fatigue. It is usually treatable with regular and consistent sleep.

However, fatigue — especially when it is chronic — is often associated with a health condition or problem. It may also be its own chronic condition, called chronic fatigue syndrome, or myalgic encephalomyelitis.

Fatigue is associated with many health conditions and lifestyle factors. The sections below will outline these in more detail.

Mental health issues

Fatigue is a common symptom of clinical depression, either due to the depression itself or associated problems, such as insomnia.

Fatigue can also result from the following mental health issues:

Endocrine and metabolic reasons

Health conditions and other factors that affect hormones can cause fatigue. These include:

Drugs and medications

Certain drugs and medications can cause fatigue. These include:

Medication withdrawal can also cause fatigue until the body adjusts. Changes in dosage can also be a cause.

Heart and lung conditions

Heart and lung conditions can affect blood flow in the body or cause inflammation and may lead to fatigue. These include:

Sleep problems

The following sleep factors can also lead to fatigue:

Chemicals and substances

Vitamin deficiencies, mineral deficiencies, and poisoning can all affect sleep and cause fatigue.

Consuming caffeinated or alcoholic beverages can also disrupt sleep, especially close to bedtime. Using products containing nicotine can also disrupt sleep.

Medical conditions

Several medical conditions can cause fatigue, including:

Fatigue can also be a symptom of infection. Some infections that cause extreme tiredness include:

Chronic pain

People with chronic pain may wake up frequently throughout the night. They may also wake up feeling tired and poorly rested, having been unable to get good quality sleep.

The combination of chronic pain and a lack of sleep can cause persistent tiredness and fatigue.

In one study on fibromyalgia and sleep, half of the individuals with fibromyalgia also had sleep apnea, which contributes to fatigue.

Being overweight or underweight

Being overweight increases the risk of fatigue by increasing the risk of conditions that have fatigue as a common symptom, such as diabetes or sleep apnea.

Carrying more weight and experiencing joint or muscle pain can lead to or exacerbate fatigue.

Similarly, people who are underweight may tire easily, depending on the cause of their condition. Eating disorders, cancer, chronic diseases, and an overactive thyroid can all cause weight loss, as well as excessive tiredness and fatigue.

Too much or too little activity

A person with fatigue may not feel able to exercise, and a lack of exercise can cause further fatigue. A lack of exercise may eventually cause deconditioning, making it harder and more tiring to perform a physical task.

Fatigue can also affect healthy individuals after prolonged, intense mental or physical activity.

The main symptom of fatigue is exhaustion with physical or mental activity. A person does not feel refreshed after resting or sleeping.

It might also be hard for them to carry out their daily activities, including work, household chores, and caring for others.

The symptoms of fatigue may be physical, mental, or emotional.

Common symptoms associated with fatigue can include:

Symptoms tend to get worse after exertion. They may appear a few hours after activity or exercise, or possibly on the next day.

Diagnosis can be difficult, as the causes and symptoms of fatigue are varied and nonspecific.

The doctor may ask questions relating to:

  • the qualities of the fatigue
  • the patterns of the fatigue, such as the times of day when the symptoms are worse or better and whether or not taking a nap helps
  • the quality of the person’s sleep
  • the person’s emotional state and stress levels

A person can aid their diagnosis by keeping a record of the total hours they sleep each night and how often they wake up each night.

The doctor will carry out a physical examination to check for signs of illness and ask the person which medications they are taking, if any.

They will also ask about lifestyle habits, including the person’s diet, caffeine use, drug use, alcohol consumption, and work and sleep patterns.

Diagnostic tests

Diagnostic tests can help diagnose the underlying cause of the fatigue. Urine tests, imaging scans, mental health questionnaires, and blood tests may be necessary depending on other symptoms.

Tests such as these can help rule out physical causes, such as infections, hormonal problems, anemia, liver problems, or kidney problems.

The doctor may also order a sleep study to rule out a sleeping disorder.

If they diagnose an illness, they will suggest appropriate treatments.

To treat fatigue effectively, a doctor needs to find and diagnose the underlying cause.

Choosing the appropriate treatment for the condition can help alleviate fatigue.

Sleep

Getting good quality sleep is an important part of managing fatigue.

To practice good sleep hygiene:

  • Aim to go to bed and wake up at the same time each day, even on days off.
  • Set the bedroom temperature at a comfortable level. The Sleep Foundation advises between 60–67 degrees Fahrenheit.
  • Make sure that the room is dark and quiet.
  • Avoid screen time an hour before sleeping, as the light and sounds from a television, computer, or phone can stimulate brain activity and affect sleep quality.
  • Avoid eating shortly before going to bed.
  • As bedtime approaches, try to slow down both physically and mentally. Taking a warm bath or listening to some soothing music can help clear the mind of stressful and worrying thoughts before going to sleep.

Keeping a sleep diary to detect patterns may also help.

Eating and drinking habits

Diet can affect how tired or energetic a person feels. Maintaining a moderate and well-balanced diet can lead to better health and better sleep.

Here are some tips to try:

  • Eat small, frequent meals throughout the day.
  • Eat snacks that are low in sugar.
  • Avoid highly processed food and follow a healthful diet.
  • Consume plenty of fresh fruits and vegetables.
  • Avoid consuming caffeine in the afternoon and evening.

There are many foods that help beat fatigue.

Physical activity

Getting regular physical activity can help reduce fatigue and improve sleep.

Those who have not been physically active for some time should introduce exercise gradually. A doctor or sports therapist can help.

People should exercise during the time of day that is most productive for them.

Yoga and mindfulness

In one older 2010 study, people with multiple sclerosis who completed 2 months of mindfulness meditation reported that levels of fatigue, anxiety, and depression fell, while their quality of life improved.

Another older 2010 study into the benefits of yoga found some improvement in symptoms of fatigue and sleep quality in cancer survivors. The 4-week program included postures, meditation, breathing, and some other techniques.

The Centers for Disease Control and Prevention (CDC) urge people to familiarize themselves with the warning signs of drowsiness on the road.

A survey they carried out found that around 1 in 25 drivers ages 18 years and above had fallen asleep while driving in the previous 30 days.

If a driver notices that they are doing any of the following, they should pull over and take a nap or change drivers:

  • yawning and blinking
  • not remembering the last few miles they have driven
  • missing an exit
  • drifting across the lane
  • driving onto a rumble strip
  • having trouble staying focused

A range of health conditions and lifestyle factors — such as diabetes, depression, and chronic pain, among others — can lead to fatigue.

If fatigue and sleepiness are affecting a person’s daily life and none of the tips in this article work, they should see a doctor for advice.

To help with diagnosis, a person can keep a diary of their sleep habits and symptoms. After making a diagnosis, a doctor will be able to suggest some appropriate treatment options.