A condition lasting for more than 6 months in which a person feels tired most of the time and may have trouble concentrating and carrying out daily activities. Other symptoms include sore throat, fever, muscle weakness, headache, and joint pain.

A disorder of ongoing, severe tiredness that interferes with a person's ability to function well, isn't improved with rest, and isn't caused by another illness.

A syndrome of unknown etiology. Chronic fatigue syndrome (CFS) is a clinical diagnosis characterized by an unexplained persistent or relapsing chronic fatigue that is of at least six months' duration, is not the result of ongoing exertion, is not substantially alleviated by rest, and results in substantial reduction of previous levels of occupational, educational, social, or personal activities. Common concurrent symptoms of at least six months duration include impairment of memory or concentration, diffuse pain, sore throat, tender lymph nodes, headaches of a new type, pattern, or severity, and nonrestorative sleep. The etiology of CFS may be viral or immunologic. Neurasthenia and fibromyalgia may represent related disorders. Also known as myalgic encephalomyelitis.

Distinctive syndrome characterized by chronic fatigue, mild fever, lymphadenopathy, headache, myalgia, arthralgia, depression, and memory loss; candidate etiologic agents include Epstein-Barr and other herpesviruses.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious, long-term illness that affects many body systems. Another name for it is chronic fatigue syndrome (CFS). ME/CFS can often make you unable to do your usual activities. Sometimes you may not even be able to get out of bed. Researchers don't yet know what causes ME/CFS. There may be more than one potential cause. It is also possible that two or more triggers might work together to cause the illness. Researchers are studying many possible causes, including: Infections; Immune system changes; Physical or emotional stress; Changes in the way cells in the body get their energy; Genetics; the illness can sometimes run in families. Anyone can get ME/CFS, but it is most common in people between 40 and 60 years old. Adult women are more likely to develop it than adult men. The primary, or core, symptoms of ME/CFS are: Not being able to do activities that you used to do before the illness, along with severe fatigue. The fatigue must last six months or longer, and it is not improved by rest.; Post-exertional malaise (PEM), which means that your symptoms get worse after any physical or mental activity.; Sleep problems. Along with the primary symptoms, to be diagnosed with ME/CFS, you need to have one or both of these symptoms: Problems with thinking and memory.; Worsening of symptoms while standing or sitting upright. This is called orthostatic intolerance. It can cause you to feel lightheaded, dizzy, weak, or faint while standing or sitting up. Some of the other symptoms that ME/CFS can cause include: Pain, including muscle pain, joint pain, and headaches; Sore throat; Tender lymph nodes (glands) in the neck or armpits; Digestive issues, like irritable bowel syndrome; Chills and night sweats; Allergies and sensitivities to foods, odors, chemicals, light, or noise. ME/CFS can be unpredictable. Your symptoms may come and go. They may change over time; sometimes they might get better, and other times they may get worse. ME/CFS can be difficult to diagnose. There is no specific test for ME/CFS, and other illnesses can cause similar symptoms. Your health care provider has to rule out other diseases before making a diagnosis of ME/CFS. Your provider will do a thorough medical exam, which will include: Asking about your medical history and your family's medical history.; Asking about your current illness, including your symptoms. Some questions they may ask could include how often you have symptoms, how bad they are, how long they have lasted, and how they affect your life.; Thorough physical and mental status exams.; Blood, urine, or other tests to check for other illnesses which could be causing your symptoms. Your provider may also ask you to see a specialist to check for other conditions which can cause similar symptoms. There is no cure or approved treatment for ME/CFS, but you may be able to treat or manage some of your symptoms. You, your family, and your provider should work together to decide on a plan. You should figure out which symptom causes you the most problems and try to treat that first. For example, if sleep problems affect you the most, you might first try using good sleep habits. If those do not help, you may need to take medicines or see a sleep specialist. Strategies such as learning new ways to manage activity can also be helpful. You need to make sure that you do not "push and crash." This can happen when you feel better, do too much, and then get worse again. When...

(fatigue syndrome, chronic) A syndrome characterized by persistent or recurrent fatigue, diffuse musculoskeletal pain, sleep disturbances, and subjective cognitive impairment of 6 months duration or longer. Symptoms are not caused by ongoing exertion; are not relieved by rest; and result in a substantial reduction of previous levels of occupational, educational, social, or personal activities. Minor alterations of immune, neuroendocrine, and autonomic function may be associated with this syndrome. There is also considerable overlap between this condition and FIBROMYALGIA. (From Semin Neurol 1998;18(2):237-42; Ann Intern Med 1994 Dec 15;121(12): 953-9)

Chronic fatigue syndrome (CFS, also called myalgic encephalomyelitis/chronic fatigue syndrome [ME/CFS]) is a syndrome of life-altering fatigue lasting > 6 months that is unexplained and is accompanied by a number of associated symptoms. Management includes validating the patient's disability, treating specific symptoms, and in some...

Chronic fatigue syndrome (CFS) is a disorder characterized by a state of chronic fatigue that persists for more than 6 months, has no clear cause, and is accompanied by cognitive difficulties. CSF was initially termed encephalomyalgia (or myalgic encephalomyelitis) because British clinicians noted that the essential clinical features of...

Chronic fatigue syndrome (CFS) is a complicated disorder characterized by extreme fatigue that lasts for at least six months and that can't be fully explained by an underlying medical condition. The fatigue worsens with physical or mental activity, but doesn't improve with rest.

Definitions of chronic fatigue syndrome (CFS) have evolved from a focus on fatigue and impairment as described in the Centers for Disease Control (CDC) criteria, to postexertional malaise (PEM)/exertional exhaustion in myalgic encephalomyelitis (ME)/CFS as defined by the Canadian Consensus Criteria, and systemic exertion intolerance...

Chronic fatigue syndrome (CFS), disorder characterized by persistent debilitating fatigue. There exist two specific criteria that must be met for a diagnosis of CFS: (1) severe fatigue lasting six months or longer and (2) the coexistence of any four of a number of characteristic symptoms, defined...