Chronic Fatigue: An Introduction
Most people will experience fatigue at some point in their lives. In most cases, fatigue:
- Refers to exhaustion during or after usual daily activities
- Refers to a lack of energy to begin these activities
- May result from exertion, lack of sleep, or illnesses such as colds
- Generally goes away after getting more rest or recovering from a cold.
However, chronic fatigue occurs when symptoms of exhaustion or lack of energy last for more than six months.
Chronic Fatigue Versus Chronic Fatigue Syndrome
Chronic fatigue is a symptom of many diseases. While
chronic fatigue syndrome (CFS) is a condition, chronic fatigue is only one symptom. In order to be diagnosed with chronic fatigue syndrome, a person must have chronic fatigue and four or more of the following symptoms:
- Substantial impairment in short-term memory or concentration
- Sore throat
- Tender lymph nodes
- Muscle pain
- Multi-joint pain without swelling or redness
- Headaches of a new type, pattern, or severity
- Unrefreshing sleep (insomnia)
- Post-exercise fatigue lasting more than 24 hours.
Causes of Chronic Fatigue
Although the cause of chronic fatigue is unknown, infection, hormone levels, and stress are also believed to play a role in its symptoms. Chronic fatigue often results from:
- Sleep disturbance in combination with chronic pain and depression
- Stress
- Physical inactivity
- Poor diet
- Medications
- Social and cultural factors
- Certain medical conditions (see below).
Regardless of the cause, chronic fatigue has a major impact on day-to-day functioning and quality of life.