Chronic fatigue syndrome (abbreviated CFS) is a long-lasting condition of extreme fatigue (i.e., weakness or loss of energy) that is not improved by bed rest.[1] Furthermore, CFS patients may experience worse chronic fatigue if they engage in physical or mental activity.
An estimated 800,000 people in the U.S. have CFS.[2] Although two to four times as many women as men are diagnosed with CFS, it is not known whether the difference in diagnosis between genders is due to an actual difference in occurrence, or merely that more women seek medical attention for the condition.[1] Most women with CFS are between the ages of 25 and 45.[2]
The nature of the onset of CFS varies in different people.[1] Some people develop CFS abruptly after having a cold, the flu, or a highly stressful time in their life.[1, 2] Other people develop CFS gradually.
Scientists have suggested that CFS may be caused by various conditions, including:[1-5]
Extreme physical or emotional stress
Iron deficiency anemia
Deficiencies in several other nutrients, including certain
vitamins
Hypoglycemia (i.e., low blood sugar)
Intolerance to certain foods
Exposure to certain chemicals, including organophosphates, in the environment
Sensitivity to a variety of chemicals in the environment
Sensitivity to certain metals used in dental fillings
Chronic condition of mild hypotension (i.e., low blood
pressure), which can result in episodes of fainting
Abnormal levels of hormones made by the adrenal glands,
hypothalamus, pituitary glands, or thyroid gland
Insufficient level of production of certain types of neurologically active molecules (i.e., neurotransmitters such as PBMC beta-endorphin)
Chronic infection with certain viruses (e.g., Coxsackie viruses B1 and B4, cytomegalovirus, Epstein-Barr virus, or human herpesvirus 6)
Allergies
Lack of proper functioning of the immune system
Presence of certain forms of certain genes in white blood cells, which may increase the risk of some people with a family history of the condition to develop CFS
Although the exact cause of CFS is not known, many scientists believe that CFS is a type of autoimmune disorder (e.g., a class of conditions in which the immune system attacks certain tissue or certain cells within the body) resulting in inflammation of the nervous system.[1] For example, a small study recently showed that 25 CFS patients had abnormal levels of activation of 16 genes in mononuclear cells (i.e., a specific type of white blood cells) in circulating blood.[3, 4] Possible reasons for the activation of some of genes include virus infection and exposure to organophosphates.
The researchers suggested that the high levels of activation observed for 15 of the genes and the low level of activation observed for one of the genes in the mononuclear cells of the blood can result in activation of T cells (i.e., a specific type of immune cell), disturbance of function of mitochondria (i.e., the energy-producing structure in cells), and abnormal functioning of the nervous system.[3] Furthermore, the levels of certain inflammatory molecules produced by the body may be increased and the amounts of certain types of immune cells may be altered in CFS patients.[2] Some scientists think that CFS may be related to another autoimmune disease, fibromyalgia.
CFS patients may experience many flu-like, yet persistent, symptoms, which may last for months or years or occur intermittently.[1] Common symptoms of CFS include unexplained, persistent, extreme fatigue, as well as the following 8 conditions:[1, 2]
Extreme exhaustion that lasts more than 24 hours following normal level of exercise or physical exertion
Unexplained soreness in the muscles
Pain moving to different joints, although swelling or redness of the joints is not present
Pain in and mild enlargement of the lymph nodes in the neck and/or armpits
Sore throat
Headaches that are different in type, or pattern, or more severe than those experienced in the past
Abnormal sleep patterns (e.g., being easily awakened by noise, having insomnia, having frightening nightmares, or sleeping much too long) and/or does not result in a feeling of being rested
Loss of short-term memory and/or loss of ability to concentrate
In the U.S., clinical diagnosis of CFS is based on a person experiencing unexplained, extreme fatigue for at least 6 months, as well as at least 4 of the above 8 primary signs and symptoms.[1]
In addition, CFS patients may experience the following signs and symptoms:[1, 2]
Allergies
Bloating
Chronic cough
Cystitis (i.e., inflammation of the bladder), especially in the absence of bacterial infection
Difficulty in doing certain mental tasks, such as performing word searches and solving math problems
Digestive disturbances, including chronic constipation and diarrhea
Dizziness
Dry eyes and dry mouth
Earache
Feeling so exhausted after waking up that patients can not get out of bed for 1 to 3 hours (i.e., a condition called dysania)
Intolerance of alcohol
Irregular heartbeat
Loss of weight
Low blood pressure, especially when standing up
Migraine headaches
Morning stiffness of the joints
Nausea
Pain in the jaw
Pain in the chest
Pain in the abdomen
Persistently abnormal (i.e., either low or slightly elevated) temperature when measured orally
Premenstrual syndrome (PMS)
Psychological disturbances (e.g., experiencing anxiety, having panic attacks, feeling depressed, and/or feeling irritable)
Rapid heartbeat (i.e., tachycardia)
Secondary infections, including yeast and viral infections
Sensations of tingling
Sensitivity to certain chemicals
Shortness of breath
Sweating without having fever in the day or night
Unsteadiness when standing with eyes closed (i.e., this is called a Romberg test)
Vision problems, including difficulty focusing, night blindness, photophobia (i.e., sensitivity to light), and tunnel vision
Moreover, some CFS patients have experienced the following complications of CFS:[1]
Side effects of medications used in treatment
Adverse effects of lack of physical activity
Depression due to both symptoms and lack of accurate or timely diagnosis
Becoming socially isolated, due to fatigue
Other limitations in lifestyle
Loss of work and related revenue
When considering a diagnosis of CFS, doctors rule out other medical conditions, psychological conditions, or medications that may be responsible for the loss of energy and other symptoms. [1, 2] Although no specific diagnostic tests or laboratory tests for CFS are available, doctors may order certain laboratory tests to rule out other conditions. The recent finding of abnormal levels of activation of genes in mononuclear cells in circulating blood in people with CFS may lead to the development of a new diagnostic test for CFS.[3, 4]
Symptoms of CFS may last for months or years.[1] Some CFS patients have symptoms that last for a long period of time, then disappear, and then reappear. Although the symptoms of some CFS patients may become worse over time, other CFS patients recover completely within 6 months, a year, or longer.
If you are experiencing fatigue that seems unrelated to your activities, is long-lasting, or is preventing you from engaging in and enjoying your everyday life, consult your integrative medical physician and your other healthcare professionals for diagnosis of your condition and guidance on therapy. Although some mainstream medical literature may state that no specific "cure" for CFS has been found yet, many lifestyle practices and treatments are available to help you recover, regain your strength, and enjoy your life. For further information, see our Q&A on treatment of chronic fatigue syndrome (CFS).
REFERENCES
1. Mayo Clinic. Chronic fatigue syndrome. 06/23/05. Accessed at www.mayoclinic.com.
2. Life Extension Foundation. Chronic Fatigue Syndrome. In: Disease Prevention and Treatment, 4rh ed. 2003. Hollywood, FL: Life Extension Media.
3. N. Naushik, D. Fear, S.C.M. Richards, C.R. McDermott, et. al. Gene expression in peripheral blood mononuclear cells from patients with chronic fatigue syndrome. Journal of Clinical Pathology. 2005; 58:826-832.
4. American Association of Retired Persons. Chronic fatigue: no doubt. AARP Bulletin. 2005; 46(8): 25.
5. J. Smith, E.I. Fritz, J.R. Kerr, A.J. Cleare,, et. al. Association of chronic fatigue syndrome with human leukocyte antigen class II alleles. Journal of Clinical Pathology. 2005; 58:860-863.
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