Fatigue is often confused with tiredness. Tiredness happens to everyone. It's a feeling you expect after certain activities or at the end of the day. Usually, you know why you are tired and a good night's sleep solves the problem.
Fatigue is a daily lack of energy. It is an unusual or excessive whole-body tiredness not relieved by sleep. It can last just for a short time (a month or less) or stay around for longer (one to six months or longer). Fatigue can prevent you from functioning normally and gets in the way of things you enjoy or need to do.
Many men who have advanced prostate cancer experience side effects. Some of these side effects result from the treatments used to slow the spread of cancer. Other side effects come from the disease itself. Understanding these side effects can relieve fears and help you cope better. So can being an active participant in your own care. Ask your doctor questions. Learn about potential symptoms and options before receiving treatments. Carefully weigh each option with your doctor's input.
Cancer-related fatigue is one of the most common side effects of cancer and its treatment. It is not predictable by tumor type, treatment, or stage of illness. Usually, it comes on suddenly, does not result from activity or exertion, and is not relieved by rest or sleep. It is often described as "paralyzing." It may continue even after treatment is complete.
What Causes Cancer-Related Fatigue?
The exact reason for cancer-related fatigue is unknown. It may be related to the disease itself or its treatments.
The following cancer treatments are commonly associated with fatigue:
Chemotherapy. Any chemotherapy drug may cause fatigue, but it may be a more common side effect of drugs such as vincristine and cisplatin. Patients often notice fatigue after several weeks of chemotherapy, but this varies among patients. Some patients feel fatigue for a few days, while others say the problem persists throughout the course of treatment and even after it is completed.
Radiation therapy. Radiation therapy can cause fatigue that increases over time. This can occur no matter where the treatment site is. Fatigue usually lasts from three to four weeks after treatment stops but can continue three months to one year after the treatment is finished.
Combination therapy. More than one cancer treatment at the same time or one after the other increases the chances of developing fatigue.
What Other Factors Contribute to Fatigue?
Several other factors could contribute to fatigue, including:
Tumor cells compete for nutrients, often at the expense of the normal cells' growth.
Decreased nutrition from the side effects of treatments (such as nausea, vomiting, mouth sores, taste changes, heartburn, or diarrhea) can also cause fatigue.
Cancer treatments, specifically chemotherapy, can cause reduced blood counts, which may lead to anemia, a blood disorder that occurs when the blood cannot adequately transport oxygen through the body. When tissues don't get enough oxygen, fatigue can result.
Medicines used to treat side effects such as nausea, pain, depression, anxiety, and seizures can also cause fatigue.
Research shows that chronic, severe pain increases fatigue.
Stress can worsen feelings of fatigue. Stress can result from dealing with the disease and the "unknowns" as well as from worrying about daily tasks or trying to meet others' needs.
Fatigue may result when you try to maintain your normal daily routines and activities during treatments. Modifying your schedule and activities can help conserve energy.
Depression and fatigue often go hand-in-hand. It may not be clear which started first. One way to sort this out is to try to understand your depressed feelings and how they affect your life. If you are depressed all the time, were depressed before your cancer diagnosis, or are preoccupied with feeling worthless and useless, you may need treatment for depression.