Fatigue

Fatigue can arise from various sources, such as physical or mental health conditions, medications, or chronic pain, among others.

While physical and mental fatigue are distinct, they often occur simultaneously. Prolonged physical exhaustion may gradually lead to mental fatigue.

Long-term poor sleep can also contribute to feelings of fatigue. Health authorities recommend that adults aim for 7–8 hours of sleep per night. However, studies suggest that approximately one-third of people in the United States report not getting enough sleep.

Maintaining a balanced diet and staying physically active can help alleviate fatigue for many individuals. Treating the underlying cause, whether it’s poor sleep or a health condition, is essential for improvement.

When fatigue poses safety risks, it becomes a significant public health issue. Those experiencing severe fatigue may exhibit behaviors similar to those who are intoxicated.

This article will explore the different types of fatigue, their potential causes, and available treatment options.

Types of fatigue

Fatigue can be categorized into two primary types: physical and mental.

1. Physical fatigue occurs when someone finds it difficult to perform usual tasks, like climbing stairs. Symptoms often include muscle weakness, and a strength test may help with diagnosis.
2. Mental fatigue, on the other hand, affects concentration and the ability to stay focused. Individuals may feel sleepy or have trouble staying awake while working.

Sleepiness vs. fatigue

Sleepiness typically results from inadequate sleep or lack of stimulation. It may also stem from conditions that disrupt sleep, such as sleep apnea or restless legs syndrome.

Sleepiness is generally short-lived and can often be resolved by maintaining consistent sleep patterns.

In contrast, fatigue—especially when chronic—may be linked to an underlying health issue or become its own persistent condition, such as chronic fatigue syndrome (myalgic encephalomyelitis).

Causes

Fatigue is common in many different physical and psychological illnesses. The fatigue may be due to the illness itself or a side effect of medication or other treatments. Sometimes, there are multiple causes that together can explain the fatigue.

Fatigue that is not caused by illness

Common tiredness is often caused by something in your lifestyle that you can address.

Changes in the body can cause fatigue. For example, it can occur if you are pregnant, in puberty, or if you have recently had a temporary illness, such as stomach flu or influenza.

Changes in life circumstances can also cause fatigue. For example, it may happen if you have just changed jobs, moved, or if you are grieving or feeling anxious.

How does it feel in illness?

Fatigue in illness is about getting tired more easily than usual. The tiredness can appear suddenly, even after small efforts. It takes longer to recover than before. Just resting doesn’t always help.

• Sometimes, it can feel impossible to do things that you usually manage without thinking. For example, getting dressed or eating.
• You may feel weak and heavy in your arms and legs.
• It may be difficult to concentrate, remember things, or make decisions.
• Your relationship with others may be affected. Some people are unable to handle other people at all. Mood and patience may change.
• Some become more emotional and feel more vulnerable than they normally do.
• Libido can decrease.
• Some people have mild symptoms and can continue with their life nearly as usual. For others, the fatigue affects their life and social interactions constantly or during certain periods.

Fatigue can stem from a variety of health conditions and lifestyle factors, which are discussed in more detail below.

Mental health issues

Fatigue is commonly a symptom of clinical depression, either due to the depression itself or related issues, such as insomnia.

Mental health conditions that may lead to fatigue include:

• Stress
• Grief
• Eating disorders
• Anxiety
• Boredom
• Emotional exhaustion or burnout
• Major life events, such as moving or divorce

Endocrine and metabolic factors

Several health issues that affect hormone levels can result in fatigue. These include:

• Cushing’s syndrome
• Kidney disease
• Diabetes
• Thyroid conditions
• Pregnancy
• Hormonal contraception, including birth control pills and implants

Medications

Certain medications can contribute to fatigue, including:

• Antidepressants
• Anxiety medications
• Antihypertensives
• Statins
• Steroids
• Antihistamines
• Sedatives

Medications that are being withdrawn or adjusted can also cause temporary fatigue.

Heart and lung conditions

Conditions affecting the heart and lungs can disrupt blood flow or cause inflammation, leading to fatigue. These include:

• Pneumonia
• Arrhythmias
• Asthma
• Chronic obstructive pulmonary disease (COPD)
• Heart disease
• Congestive heart failure

Sleep-related factors

Factors disrupting sleep can also lead to fatigue, including:

• Late-night work
• Shift work
• Jet lag
• Sleep apnea
• Narcolepsy
• Insomnia
• Gastroesophageal reflux disease (GERD)

Chemicals and substances

Deficiencies in vitamins or minerals, as well as poisoning, can interfere with sleep and cause fatigue.

Substances like caffeine and alcohol can also disrupt sleep, particularly when consumed late in the day. Nicotine can have a similar effect.

Medical conditions

Several medical conditions are linked to fatigue, including:

• Anemia
• Diabetes
• High blood pressure
• Obesity
• Heart disease
• Chronic fatigue syndrome
• Fibromyalgia
• Rheumatoid arthritis
• Inflammatory bowel disease
• Cancer, along with its treatments like chemotherapy
• Blood loss

Fatigue can also be a symptom of various infections, including:

• Malaria
• Tuberculosis
• HIV
• Hepatitis
• Flu
• Infectious mononucleosis
• Cytomegalovirus

Chronic pain

Individuals dealing with chronic pain often experience sleep disruptions, which in turn cause persistent fatigue. The combination of poor sleep and ongoing pain can lead to continuous tiredness.

Studies have shown that individuals with fibromyalgia, for instance, often experience both sleep apnea and fatigue.

Weight concerns

Both being overweight and underweight can contribute to fatigue. Obesity increases the likelihood of conditions such as sleep apnea or diabetes, both of which cause fatigue.

Excess weight can lead to joint and muscle pain, exacerbating fatigue. Similarly, those who are underweight may tire easily due to underlying conditions, including eating disorders, cancer, or hyperthyroidism.

Activity levels

A lack of physical activity can lead to fatigue. Inactive individuals may find it increasingly difficult to perform daily tasks due to physical deconditioning. However, overexertion can also cause fatigue, even in healthy individuals.

Symptoms of fatigue

The most notable symptom of fatigue is an overwhelming sense of exhaustion, even after rest or sleep. Everyday activities such as work, household chores, and caregiving may become more difficult to manage.

Fatigue symptoms may be physical, mental, or emotional, and they can include:

• Aching or sore muscles
• Lack of motivation or apathy
• Daytime sleepiness
• Trouble concentrating or learning new things
• Digestive issues like bloating or constipation
• Headaches
• Irritability
• Slowed response times
• Vision problems, such as blurry sight

Symptoms tend to worsen after physical or mental exertion and may not appear until a few hours later or even the next day.

What happens in the body?

Sometimes, fatigue has a clear connection to an illness or treatment. Other times, it is difficult to find such a link. Sometimes, a cause of fatigue can lead to more conditions that contribute to fatigue and amplify it.

Here are some examples of what can happen in the body during illness and treatment that causes fatigue:

• You may have too much or too little of something like a hormone or another substance necessary for your well-being.
• The illness or treatment may sometimes cause substances that are difficult for the body to handle.
• A bodily function may be impaired, such as the ability to absorb nutrients. This leads to weight loss and lack of energy.
• The illness or treatment may make it hard to sleep, eat, or cause stress and anxiety.

Diagnosis

Diagnosing fatigue can be challenging, as it is often a symptom of multiple, nonspecific conditions.

A doctor may ask questions about:

• The nature and timing of fatigue
• Sleep quality
• Emotional state and stress levels

A sleep diary can help the doctor understand the person’s sleeping habits and patterns.

The doctor will also conduct a physical examination, review medications, and assess lifestyle habits like diet, alcohol consumption, and work patterns.

Diagnostic tests

Tests like blood work, urine samples, and imaging scans can help identify the underlying causes of fatigue, such as infections, hormonal imbalances, or organ issues.

Sleep studies may also be recommended to rule out sleep disorders.

Once a cause is determined, treatment options will be explored.

Treatment

Effective treatment of fatigue hinges on identifying and addressing the underlying cause.

Sleep management

Proper sleep hygiene is key to managing fatigue. Recommendations include:

• Consistent bedtimes and wake times
• A cool, quiet, and dark bedroom
• Avoiding screen time before sleep
• Limiting late-night meals
• Relaxing activities, such as taking a warm bath or listening to calming music, before bedtime

A sleep diary can help identify patterns and improve sleep quality.

Diet and hydration

Eating balanced meals throughout the day can help reduce fatigue. Tips include:

• Eating smaller, more frequent meals
• Choosing low-sugar snacks
• Avoiding processed foods
• Incorporating plenty of fruits and vegetables
• Reducing caffeine intake in the late afternoon

Physical activity

Regular exercise helps reduce fatigue and enhances sleep. Starting slowly, especially for those who have been inactive, is important. A sports therapist or doctor can assist in creating a tailored plan.

Yoga and mindfulness

Studies have shown that mindfulness meditation and yoga can help reduce fatigue and improve quality of life for individuals with conditions like multiple sclerosis and cancer.

Driving issues

Fatigue can impair driving ability. The CDC advises drivers to recognize the signs of drowsiness, such as yawning or difficulty staying focused. Drivers should pull over and rest if these symptoms occur.

What can I do myself?

Here are a few things you can do to reduce fatigue:

• Engage in some physical activity every day. Choose an activity that feels good and comfortable for you.
• Rest for up to 15 minutes when you feel you need a break. Rest both before and after something you want or need to do.
• Only do what you really want or need to do. Focus on the energy and motivation you have right now.
• Let others help you with what needs to be done, if possible. It could be a close one picking up children from school or shopping for groceries online.
• Do one thing at a time, and a little at a time.
• Avoid disturbing stimuli, such as lights or sounds.
• Be cautious when lifting or carrying things if you have pain.

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