Fatigue associated with mental or physical exertion is usually of short duration. However, there are many medical conditions in which persistent fatigue is a symptom.   Fatigue can result from result of poor diet, viral or bacterial infections, lack of exercise and other factors. But in these cases, medical intervention or a change in lifestyle can make all the difference. (see our previous post to learn about the causes of fatigue).

Persistent Fatigue

Chronic or persistent fatigue is present in a variety of different conditions. At times that fatigue is mild, but it is often severe enough to be debilitating.  Unfortunately, there is a poor prognosis for a cure for these disorders. And treating the symptoms is sometimes all that can be accomplished. The presence of fatigue in numerous unrelated conditions makes an accurate diagnosis of the underlying cause(s) difficult.

Diseases Associated with Persistent Fatigue

Among the common treatable conditions that cause mild to moderate persistent fatigue are anemia, hypothyroidism, diabetes, sleep apnea and heart disease.

  • Anemia develops when there is an iron deficiency in the blood. The body cannot produce adequate amounts of oxygen-carrying hemoglobin. This type of fatigue is relieved by a simple change of diet to include more iron.
  • Hypothyroidism and diabetes respond well to hormone replacement therapy, using synthetic analogs of natural hormones (thyroxine and insulin respectively), as well as dietary modifications.
  • Sleep apnea occurs when the airway is obstructed due to muscle relaxation or disruption of the brain’s control of breathing. In severe cases, it causes a repeated stopping and starting of breathing during sleep 30-40 times per hour. Treatment consists of mechanical or surgical intervention to keep the airway open or electrical stimulation to restore proper neural control.
  • Heart disease is counteracted with increased (moderate) exercise or a change in diet and lifestyle. Surgical intervention often restores the heart’s ability to supply blood to the body, which frequently relieves the associated fatigue.

In some diseases, it is much more difficult to provide relief from persistent fatigue. Many of these are autoimmune diseases, such as multiple sclerosis, Parkinson’s disease, rheumatoid arthritis, lupus and Sjogren’s syndrome, where the immune system attacks the body’s own tissues and organs. Most autoimmune diseases alternate between periods where the symptom are severe and periods when the symptoms appear to be absent. There is no “cure” for autoimmune diseases and treatment is limited to reducing the number and intensity of flare-ups.

Chronic Fatigue Syndrome

Finally, one of the most mysterious and intractable of the disorders associated with severe long-term fatigue is Chronic Fatigue Syndrome.  Patients with CFS experience severe persistent fatigue that is often exacerbated by even mild exertion.

Our next Focus on Fatigue post will discuss CFS in more detail and about potential therapies.