I had a cold last week. Not a momentous event, I know, but it did make me think. Normally, I think I have a lot of energy. I can work a full day, and still have the energy to do things around the house. With the cold, though, I dragged my way through work, feeling as though I were thinking at half-speed. One night, I crawled into bed at 8:30 and slept until my alarm went off the next morning. This kind of fatigue gave me some appreciation on a small scale for what people with chronic illnesses go through on a large scale.
Fatigue actually seems to have a few different components to it. One is general tiredness. A second is what psychologists refer to as vitality or vigor. A third aspect of fatigue influences people's ability to think. Being sick can create any and all aspects of fatigue. And for people with chronic illnesses, interventions to help relieve fatigue may not help all of these aspects.
General tiredness is the easiest of the aspects of fatigue to understand. This is just the element of fatigue that people feel when they feel as though they need to sleep more.
Vitality and vigor is different from tiredness. You might not feel like sleeping, but that doesn't mean that you have much energy to get out of bed and do things. Thinking also requires energy. We have all had days where we are awake, but we don't think we can do anything more taxing than to stare at a TV screen as the images go by.
Finally, even if we feel awake and even have some energy level, we might not feel as though we can concentrate much. It might take too much effort to pay attention to a particular conversation or to think carefully about a thought.
The issue of fatigue has gotten a lot of attention in the literature on cancer treatment. It is well known that patients with cancer experience a variety of symptoms of fatigue. Some of these symptoms emerge as the body tries to fight the disease. Some symptoms occur as people deal with the noxious drugs that are used to treat cancer. This cancer related fatigue is an important part of the human cost of the disease.
There was a recent review of treatments for cancer-related fatigue by Kangas, Bovbjerg, and Montgomery that appeared in the September, 2008 issue of the journal Psychological Bulletin. This paper examined the results of a large number of studies that have been over several years.
An important conclusion from this review is that combating fatigue requires a variety of approaches. That is, it is not enough just to exercise or just to take part in stress reduction, or just to see a counselor. Often, single interventions would help relieve one type of fatigue, but would not affect all of the components. So, patients in a given study might feel less tired, but not have more energy. Or they might have increases in energy, but still tire easily.