Chronic fatigue causes, symptoms, risk factors, diagnosis, and treatment. Chronic fatigue is a common complaint of people with arthritis and rheumatic diseases. Risk factors that may cause or contribute to fatigue include: poor sleep, chronic pain, stress, depression, anxiety, inflammation, inactivity, diet, and drug side effects. Learn more about living and coping with fatigue.

Chronic fatigue syndrome is a condition of prolonged and severe tiredness or weariness (fatigue) that is not relieved by rest and is not directly caused by other conditions. To be diagnosed with this condition, your tiredness must be severe enough to decrease your ability to participate in ordinary activities by 50%.

Fatigue is an excessive feeling of tiredness, lack of energy, or exhaustion accompanied by a stong desire to rest or sleep. Many underlying conditions can cause fatigue and it is essential to find the cause.

Some people with CFS develop a condition in which their heart rate increases and their blood pressure drops when they stand or sit up from a reclining position. This is often described as feeling "lightheaded" or feeling faint or dizzy. This condition is called orthostatic hypotension. Depression is common and can make your other symptoms worse. Antidepressant medicines can help you feel better.

CFS began receiving widespread attention in the mid-1980s, after reports of about 100 cases in the Lake Tahoe area of California. Questions immediately arose as to whether the ill-defined mix of symptoms amounted to a discrete disease at all, and if so, whether it was a new condition.

In addition to fatigue, there may also be muscle pain, joint pain not associated with redness or swelling, short-term memory loss, and an inability to concentrate. Some people with chronic fatigue syndrome also experience difficulty sleeping, swollen lymph nodes, and/or mild fever.

The concurrent occurrence of 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; and post-exertional malaise lasting more than 24 hours. These symptoms must have persisted or recurred during 6 or more consecutive months of illness and must not have predated the fatigue.

Allergic reactions to food, food intolerance (hypersensitivity), refined food, junk foods, food additives, and chemical contaminants in food can alter our moods and lead directly or indirectly to a constant state of low energy. People with Chronic Fatigue Syndrome frequently have sensitivities to foods, chemicals and other inhalants. These may be classical allergies – which are IgE (Immunoglobulin Type E)-mediated sensitivities or food intolerance (which is not IgE-mediated, so allergy tests, such as skin prick tests, are negative) and chemical intolerance are especially common.

Most patients with FMS say that they ache all over. Their muscles may feel like they have been pulled or overworked. Sometimes the muscles twitch and at other times they burn. The pain tends to be felt as diffuse aching or burning, often described as head to toe. It may be worse at some times than at others. It may also change location, usually becoming more severe in the parts of the body that are used the most.