From the Guidelines
Fatigue symptoms include persistent tiredness, lack of energy, difficulty concentrating, muscle weakness, headaches, and slowed reflexes, as defined by the most recent guidelines 1. These symptoms can be accompanied by irritability, reduced motivation, impaired decision-making, and a general feeling of exhaustion that isn't relieved by rest. Physical manifestations can include sore muscles, heavy eyelids, and a feeling of heaviness in the limbs. Sleep disturbances are common, with either insomnia or excessive sleepiness. Some key points to consider when evaluating fatigue include:
- Onset, pattern, and duration of fatigue
- Associated or alleviating factors
- Disease status and risk of recurrence
- Treatable contributing factors, such as comorbidities, medications, and nutritional issues
- The need for referral to a specialist or supportive care provider, as outlined in the guidelines 1. Fatigue differs from normal tiredness as it persists despite adequate rest and significantly impacts daily functioning. It can result from various causes, including medical conditions (anemia, thyroid disorders, infections), psychological factors (depression, anxiety, stress), lifestyle issues (poor sleep habits, overexertion), or medication side effects. If fatigue persists for more than two weeks, interferes with daily activities, or is accompanied by other concerning symptoms like unexplained weight loss or fever, medical evaluation is recommended to identify and address the underlying cause, as emphasized in the guidelines 1.
From the Research
Symptoms of Fatigue
The symptoms of fatigue can be complex and multifaceted, affecting both physical and mental domains. Some common symptoms of fatigue include:
- Weariness unrelated to exertion levels 2
- Lack of energy 3
- Difficulty concentrating or paying attention 4
- Reduced motivation 4
- Sleep disturbances 4
- Pain 4
- Reduced physical functioning 4
- Lower self-efficacy concerning fatigue 4
- Enhanced perception of effort and limited endurance of sustained physical and mental activities 5
Classification of Fatigue
Fatigue can be classified in various ways, including:
- Acute or chronic 6
- Central or peripheral 5
- Physiologic or pathologic 6
- Spontaneous or triggerable 6
- Resistant or irresistant to preconditioning, training, or attitude 6
- Prominent or collateral experience 6
- Accessible or inaccessible to any type of treatment or intervention 6
Factors Influencing Fatigue
Several factors can influence fatigue, including: