Chronic fatigue syndrome (CFS), also known as immune dysfunction syndrome, is characterized by debilitating fatigue-experienced as exhaustion and extremely poor stamina, neurological problems, and a variety of flu-like symptoms. It is estimated that over 1 million people in the United States suffer from CFS. The condition takes a tremendous personal and social toll. It occurs most frequently in women aged 40-60 and is as disabling as multiple sclerosis and chronic obstructive pulmonary disease. Many physicians still doubt that CFS is an actual disease, but believe it is a component of a psychological disorder or a symptom of other physical problems similar to anemia and high blood pressure.
Other core symptoms include general pain, mental fogginess, gastrointestinal problems, headaches, sore throat, sleep disorder, and abnormal temperature. The severity of symptoms varies widely among people; and over time, will also vary for the same person. It can differ between getting unusually fatigued following stressful events, to being totally bedridden and completely disabled. The symptoms will also come and go over time.
Symptoms and Diagnosis of Chronic Fatigue Syndrome
After eliminating other identifiable causes of CFS symptoms, the Centers for Disease Control define CFS as a distinct disorder with specific physical signs.
Four or more of the following symptoms must have been present for longer than six months:
- Short-term memory loss or a severe inability to concentrate that affects work, school, or other normal activities.
- Sore throat.
- Muscle pain.
- Pain without redness or swelling in a number of joints.
- Intense or changing patterns of headaches.
- Un-refreshing sleep.
- After any exertion, weariness that lasts for more than a day.
Often, the condition first appears as a viral upper respiratory tract infection marked by some combination of fever, headache, muscle aches, sore throat, earache, congestion, runny nose, cough, diarrhea, and fatigue. Typically, the initial illness is no more severe than any cold or flu. Other symptoms reported with CFS but not part of the criteria include intolerance to alcohol, irritable bowel syndrome, dry eyes and mouth, impaired circulation in the hands and feet, visual disturbances, and painful menstrual periods in women.
The fatigue must be severe as indicated by the following:
- Sleep or rest does not relieve it.
- The fatigue is not the result of excessive work or exercise.
- The fatigue substantially impairs a person’s ability to function normally at home, at work, and in social occasions.
- Even mild exercise often makes the symptoms, especially fatigue, much worse.
The fatigue must be a new, not lifelong, condition with a definite time of onset and the symptoms must persist. In ordinary infections, symptoms go away after a few days; but in CFS, the fatigue symptoms continue for months to years.
Causes of Chronic Fatigue Syndrome – Some Theories
Unfortunately, no primary cause has been found that explains all cases of CFS. It is not clear what sequence of events actually leads to the fatigue and other prominent symptoms of this disorder-there is no specific brain or nervous system abnormality that experts can point to. Also, there is no definite way to diagnose CFS using objective measures, such as blood tests or brain scans.
Current research is looking at the cause of CFS as being a combination of neuro-endocrine dysfunction, brain abnormalities, viruses, environmental toxins, and genetic predisposition. Possible viral causes include HHV-6, other herpes viruses, entero-viruses, and retro-viruses. Additionally, co-factors, such as genetic predisposition, stress, environment, gender, age, and prior illness, appear to play an important role in the development and course of the illness.
For example, a person may experience a preceding moderate-to-serious physical illness (a chronic viral infection) or emotional event (a bout of depression). Such events, alone or in combination, may interact with specific neurological and genetic abnormalities to trigger the event. Inheritance, then, may play a role in roughly 30% to 50% of cases, similar to the influence thought to occur in depression or alcoholism, even though specific genes have not been identified.
Also, Chronic Fatigue Syndrome has been categorized by some health professionals as either sudden onset or gradual onset, with each category having a different cause. Sudden-onset CFS may be triggered by a virus or neurological abnormality, while gradual-onset CFS might have a psychological cause. For example, many people report their CFS began after an episode with a cold, bronchitis, hepatitis, intestinal bug, or mononucleosis (sudden onset). Others have said their CFS symptoms started during a period of high stress and developed more gradually (gradual onset), with no clear illness preceding it.
Most of the features of Chronic Fatigue Syndrome resemble those of a lingering viral illness. In up to 80% of cases, chronic fatigue syndrome starts suddenly with a flu-like condition. Therefore, many researchers have focused on the possibility that a virus or some other infectious agent causes the syndrome. The virus or bacteria infects the body, causes immune abnormalities, and is then eliminated. It leaves behind a damaged immune system that continues to cause flu-like symptoms even in the absence of the virus. Another theory states that an abnormal immune response reactivates the virus that had persisted in a latent inactive stage after the initial infection.
(Note that not all CFS patients show signs of infection, and experts are divided on whether infections play any role in this disorder-most cases of CFS occur sporadically, cropping up in individuals without appearing to be contagious; plus, there is no evidence that CFS is spread through casual contact, such as shaking hands or coughing, or by intimate sexual contact.)
Research studies have found several CFS patients to possess immune system irregularities, although there is no consistent pattern-some components are over-reactive, others are under-reactive. A majority of CFS patients have allergies to foods, pollen, and metals (nickel or mercury). Like viral infections, allergens may trigger a cascade of immune abnormalities leading to CFS. People with both allergies and emotional disorders (anxiety or depression), may be more vulnerable to a harmful overreaction of the immune system that can cause fatigue, joint aches, and fever, as well as hormone and brain chemical disturbances.
Other CFS patients have observed deficiencies in stress hormones, or cortisol levels. These shortages may be the reason why CFS patients have an impaired and weaker response to the psychological or physical stresses of infection or exercise. Other research has shown that elevated levels in the brain of certain neurotransmitters are associated with fatigue-some patients with CFS have abnormally high levels of the neurotransmitters serotonin (a chemical messenger in the brain) and dopamine.
A number of patients with CFS show abnormalities in the central nervous system, including spots of brain inflammation and abnormal levels of certain hormones. Of particular interest to researchers are higher incidences of abnormalities in the hormone system known as the hypothalamus-pituitary-adrenal (HPA) axis-CFS patients tend to have an under-active HPA-axis. This system produces or regulates hormones and brain chemicals that control sleep, response to stress, and depression.
Some Chronic Fatigue Syndrome patients also have a condition known as neurally mediated hypotension (NMH). NMH causes a dramatic drop in blood pressure-a result of a central nervous system disturbance that signals the heart to slow down and lower blood pressure when a person stands up, even for a short five to ten minutes. Blood accumulates in the feet and legs before circulating back up to the heart. Its immediate effect can be lightheadedness, nausea, and fainting.
Other experts believe that CFS is a disorder of the sleep-wake cycle. They argue that some mentally or physically stressful event, such as a viral infection, may disrupt natural circadian rhythms, and that an inability to reset these rhythms results in a perpetual cycle of sleep disturbances. Poor sleep patterns cause activity avoidance, which in turn leads to physical debilitation and the onset of CFS symptoms.
Psychological, personality, and social factors are strongly associated with chronic fatigue in most, but not all, patients. In many cases, CFS also promotes psychological, emotional, and social dysfunction. The complex relationship between physical, emotional, and social factors has yet to be fully understood; these elements are unlikely to be a primary cause of CFS, but they may play a role in increasing susceptibility to onset or perpetuation of the disorder.
Coping and Managing Chronic Fatigue Syndrome
An effective treatment for chronic fatigue syndrome has yet to be found. However, you can learn how to manage the fatigue or improve your quality of life and the level at which you can function, despite your symptoms. The lack of any proven effective treatment can be frustrating. If you have CFS, health experts recommend that you try to maintain good health by
- Eating a balanced diet and getting adequate rest
- Exercising regularly but without causing more fatigue
- Pacing yourself-physically, emotionally, and intellectually – because too much stress can aggravate your symptoms.