Fatigue is by far the most common - and for many the most distressing - symptom affecting people with cancer. At its worst, cancer-related fatigue is a draining, unrelenting exhaustion that impedes the ability to enjoy life and carry out daily activities.

Many patients with cancer neglect to tell their doctors they are experiencing fatigue because they incorrectly believe nothing can be done to relieve it. The good news is that there are measures you can take to minimize the adverse effects of fatigue and boost energy.

Causes of fatigue

Because numerous factors are associated with fatigue (i.e., anemia, cancer treatments, the cancer itself, depression), it can be challenging for a doctor to identify the exact source of fatigue.

Fatigue generally occurs when a tumor spreads to the bone marrow and causes anemia (a reduction in red blood cells that carry oxygen to cells), or less directly, when it creates toxic substances in the body that disrupt cell functions. Fatigue is an early symptom of leukemia (a cancer that originates in blood-forming tissue) and it may be a symptom for people with lung and other cancers that affect breathing.

Cancer treatments including chemotherapy, radiation, bone marrow transplants and biologic therapies also are known to sap energy. Anti-cancer drugs not only attack malignant cells, but strike at fast-growing healthy cells, including red blood cells, inducing anemia and its subsequent fatigue. The symptom often lessens or disappears when treatment ends, but sometimes it lingers.

Other factors linked to fatigue include:

• Pain
• Depression and anxiety
• Inactivity
• Sleep problems
• Nutritional deficiencies
• Medications (such as antihistamines, antidepressants, narcotics and anti-nausea drugs)
• Other medical conditions

Managing fatigue

Informing your health care providers about the severity of your fatigue can help them determine the likely cause (or causes) of your fatigue and suggest ways to improve your quality of life. Physicians may consult the Cancer-Related Fatigue guidelines from the NCCN Clinical Practice Guidelines in Oncology ™ for approaches to managing cancer-related fatigue.

Consider each of the following strategies for beating the effects of fatigue:

• Exercise. It may require considerable effort to get up and move around, but increasing your physical activity may actually reduce fatigue. Studies show that cancer patients who exercise are less tired and depressed and sleep better than patients who don’t exercise. (See “Exercising During Cancer” for more tips.)
• Nutrition counseling. Many patients with cancer lose weight and are unable to eat normally due to treatment-related nausea, vomiting and anorexia. Ask your doctor to refer you to a nutrition counselor who can work with you to ensure that you are getting enough calories, fluids, protein and other nutrients to help prevent fatigue and increase energy.
• Psychosocial measures. The emotional burden of cancer can be exhausting. There is evidence that reducing stress, anxiety and depression can have a beneficial effect on fatigue. Counseling, joining a support group, or learning stress management techniques may strengthen your ability to cope, elevate mood and, in turn, restore vigor. Contact the American Cancer Society or the The Wellness Community to locate support groups in your area.
• Rest. It is important to conserve energy and undertake only the most important activities at the times when you have the most energy. Keep a log of the periods when you are most and least tired. Move around and/or exercise at the times you are well rested and have the most energy so that you will not feel discouraged if you can’t complete a task. Be realistic about your limitations and don’t be hard on yourself. Don’t be too shy or too proud to accept help from someone who can take care of chores, driving, cooking, etc., when you are not up to it.
• Distraction. Try “escaping” from your fatigue by listening to your favorite CDs, reading a juicy novel, relaxing with friends, or watching a funny movie. Some hospitals have implemented “Strength Through Laughter,”  humor therapy for people with cancer and other chronic illnesses.
• Relaxation therapy. Many people with cancer suffer from disrupted sleep patterns. Practicing relaxation techniques, limiting caffeine to the morning, keeping naps short and having good sleep habits - such as going to bed and rising at the same times each day - promote improved sleep. Massage therapy, yoga and mindfulness exercises may also be helpful.
• Renewal through nature. Simple activities like sitting beside a lake, working in the garden, and bird watching have been found to restore attention and decrease fatigue in cancer patients.
• Medications. Sometimes antidepressants for depression and/or anxiety or erythropoietin for anemia may be helpful in combatting fatigue. Stimulants, such as methylphenidate hydrochloride (Ritalin), are being tested in clinical studies for use in relieving fatigue in patients with cancer, but evidence is inconclusive as to whether they work. Other medications may be prescribed if the cause of fatigue is found to be unrelated to cancer, such as an underactive thyroid. If a drug that you are taking or have been prescribed has fatigue as a side effect, ask your doctor if the drug will still be effective if you reduce the dosage.