Fatigue is a nearly universal human experience characterized by an overall feeling of tiredness, lack of energy, exhaustion, weariness, or sleepiness. It can be brought on by prolonged mental or physical activity, inadequate rest, specific medical conditions, or even everyday stressors. Fatigue affects people both physically and mentally. On a physical level, muscles may feel weaker during exercise or daily tasks, movements may seem slower or more difficult, and there is an overall sense that the body cannot continue exerting itself at the same intensity. Mentally, people often report problems with concentration, memory, decision-making, irritability, and mood. There are two main types of fatigue:
- Acute fatigue comes on suddenly after short-term exhaustion. This is the tiredness felt after a long workday, an intense workout, or a mentally taxing project. Acute fatigue usually resolves with adequate rest.
- Chronic fatigue persists over time, often for months or years. It may be every day or intermittent fatigue. Common causes include sleep disorders, depression, anxiety, cancer, heart disease, autoimmune diseases, endocrine disorders, and more. Chronic fatigue requires assessment by a healthcare provider.
- Decreased motivation, energy, or endurance
- Difficulty concentrating, remembering details, making decisions
- Physical symptoms like muscle weakness, headaches, lightheadedness
- Increased effort needed for physical or mental tasks
- Sleepiness, lack of mental clarity, slower reaction times