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Fighting fatigue: Search out reasons for chronic tiredness
Sleep apnea
Chronic fatigue syndrome

Underlying the wearinessM
Underlying the wearinessM

Unmanaged stress and anxiety are notorious fatigue triggers. But these physical conditions may also cause unrelenting tiredness:

  • Chronic anemia. Are you often pale, dizzy and exhausted by walking up a flight of stairs? A blood test can reveal if you have anemia.
  • Diabetes. Although this is not the most common cause of fatigue, it is one of the most dangerous if left untreated. If your fatigue is accompanied by blurry vision, excessive thirst and/or frequent urination, see your doctor.
  • Hypoglycemia. People with this condition, in which blood-sugar levels plummet, can manage it by eating small meals and watching their carbohydrate intake. A special blood test can confirm a diagnosis of hypoglycemia.

Fatigue is a feeling of weariness that makes it hard to concentrate, slows down reflexes and breaks down a person’s ability to cope with stress. It’s normal to feel tired after a late night, when you have a cold or after vigorous exercise. In those cases, fatigue usually resolves itself in a day or two, or a couple of weeks at most if you’ve got a bad case of the flu.

What about fatigue that lasts more than two weeks? Chronic (ongoing) fatigue is a symptom that accompanies many illnesses. Descriptions of conditions that commonly cause chronic fatigue follow. It’s important to get help for chronic fatigue, both because it may indicate serious disease and because it’s important for personal safety. Daytime sleepiness is a contributor to many deaths and injuries from automobile crashes and other accidents.

Sleep apnea

People with sleep apnea experience short periods in which they stop breathing during sleep. The muscles in the walls of the throat relax so that the walls collapse on themselves and block the flow of air. After 10 to 30 seconds during which no air is being exchanged, the sleeper enters a lighter level of sleep and the muscles regain their normal stiffness, which allows normal breathing again.

The frequent sleep disturbances rob the body of the deep sleep it needs to restore itself. The most common symptoms are drowsiness, fatigue and lack of energy. Other symptoms include:

  • clumsiness
  • poor concentration or difficulty following instructions
  • depression, sadness, edginess and irritability
  • morning headaches
  • reduced interest in sex

Obesity is a common cause of sleep apnea. Many patients are cured when they lose excess weight. In some cases, doctors may recommend the use of a machine that delivers air (through a mask placed over the nose) at a pressure somewhat higher than that of the surrounding air. The increased pressure keeps upper airway passages open.


A variety of factors contributes to depression. Low levels of the neurotransmitter serotonin (a brain chemical) are part of the problem. Depression tends to run in families, so it seems that a person’s genes can make him or her more susceptible to depression. In addition, unmanaged stress can trigger depressive episodes.

The eight classic symptoms of depression are:

  • fatigue or loss of energy
  • depressed mood for most of the day
  • disturbed appetite or change in weight
  • disturbed sleep
  • loss of interest in previously pleasurable activities, inability to enjoy usual hobbies or activities
  • feelings of worthlessness and excessive guilt
  • difficulty concentrating or thinking clearly
  • suicidal thoughts or actions

Most experts agree that the best treatment plans for depression include medication and psychotherapy to help patients understand the sources of their depression and find other ways of coping with inner conflicts.

Chronic fatigue syndrome

As its name suggests, fatigue is the primary symptom of this syndrome (a syndrome is a constellation of symptoms). For a patient to be diagnosed with chronic fatigue syndrome (CFS), his or her case must meet the following criteria:

For six months or longer, the patient must have had severe, chronic fatigue that has led to a significant reduction in previous levels of occupational, social or personal activities. Other medical conditions that cause chronic fatigue must have been ruled out by clinical diagnosis. The fatigue must be of definite onset (in other words, not something that has been a lifelong problem).

In addition to fatigue, the patient must have four or more of the following symptoms:

  • substantial impairment in short-term memory or concentration
  • sore throat
  • tender lymph nodes
  • muscle pain
  • multijoint pain without swelling or redness
  • headaches of a new type, pattern or severity
  • unrefreshing sleep
  • postexertion malaise lasting more than 24 hours

At one time, doctors thought CFS was caused by a virus called Epstein-Barr. That theory has been disproved. However, no other cause has been identified. For that reason, treatment is directed at relieving symptoms. In general, patients with CFS are encouraged to avoid unusual physical or emotional stress. Modest, regular exercise is important to avoid losing more physical strength. Psychotherapy and supportive counseling can help patients cope with this chronic illness.