“Why Am I So Tired?” Fatigue in Patients with Serious Illness

Fatigue is one of the most common symptoms in patients with serious illness. While patients with any disease can experience fatigue, it has been found in as many as 90% of patients with advanced cancer. Fatigue has three main clusters of symptoms: becoming easily tired and reduced ability to maintain performance; generalized weakness; and mental fatigue, including decreased ability to concentrate and memory loss.

There are many causes of fatigue in patients with serious illness. These include untreated pain; medication side effects; dehydration; infection; generalized physical weakness; hormonal abnormalities (e.g. problems with how the thyroid or adrenal hormones are working); imbalances in the chemistry of the blood (e.g. low sodium, high calcium); anemia (low blood count); psychological issues (e.g. depression, anxiety); and weight loss due to the underlying disease. Patients may have several causes of fatigue, and at times it can be difficult to determine exactly why they have this symptom.

The first step in improving fatigue is to tell your doctor about it. While many clinicians will ask about symptoms like pain and shortness of breath, unfortunately, not all will ask about fatigue. Tell your doctor how severe your fatigue is, how it affects your day-to-day life and if there is any pattern to it (e.g. worse in the afternoon, better in the morning).

The treatment of fatigue involves three things: lifestyle or behavioral changes, medications used specifically to treat fatigue and treatments aimed at reversing or correcting the underlying cause(s). Behavior modifications include changing activities and daily routines, such as adjusting daily activities (e.g. reducing housework) and/or enlisting others to help with certain activities; rearranging daily schedules depending on the pattern of your fatigue; and spending more time in bed or alternating exercise with rest if physical weakness is a factor in your fatigue.

Medications that have been shown to improve fatigue include corticosteroids, megestrol acetate (similar to progesterone) and the use of stimulant medications. All of these medications have side effects, and studies examining their effectiveness have shown varying success. So the benefits and side effects of each of these medications should be discussed with your doctor.

Finally, the treatment of any underlying causes of fatigue should be investigated. For example, infections can be treated with antibiotics. Lab tests may find abnormalities in hormones or chemical imbalances that can be corrected with fluids or medications. Treatment of psychological problems may also improve fatigue and overall quality of life. Patients who are physically weak may benefit from physical and occupational therapy, which can increase muscle mass and overall energy levels. If your fatigue seems to be related to a new medication (e.g. new pain medication), discuss this with your doctor and find out if another medication can be used or if the side effect will lessen over time.

In conclusion, fatigue in patients with serious illness is common and often related to one or more underlying physical or psychological causes. While fatigue cannot always be cured, there are many treatments that may help improve your overall energy level and quality of life.

Adapted from Sweeney C, Neuenschwander H, Bruera E. Fatigue and asthenia. In: Doyle D, Hanks G, Cherny NI, Calman K, eds. Oxford Textbook of Palliative Medicine. 3rd ed. New York: Oxford University Press; 2005:560-66.