"I was always tired. From the moment I would wake up in the morning until the time I went to bed I would have a lack of energy. It did not make sense for me to feel always tired yet I did. I have not ever led an extravagant lifestyle, I do not make it a habit of being on the run all the time, and I certainly do not have the stress level of other folks the way a single parent does."
That quote was from a patient suffering from Chronic Fatigue Syndrome, but needless to say there are many causes of illness which have similar effects. Sadly doctors frequently have difficulty differentiating the ultimate causes and aren't always able to provide relief from fatigue.
As an example consider this patient quote: "Yet there I was, waking every day feeling lousy and being always tired. It just wasn't any way to live but I had been to the doctor numerous times, probably an average of three or four times a year for various ailments and just general malaise. It finally cam to a head one day this year when I had simply had enough. I was fed up with being always tired. I went to my doctor on a day I was feeling normal and said, 'Listen, today is like any other day for me, and I feel just plain lousy. I felt lousy yesterday, I feel bad today, and odds are pretty good tomorrow is going to be the same. I've had it!'"
Comments like these are common for people suffering from long term illnesses, whether it is an ingrained pitched battle with something like sinusitis, or perhaps continuing viral or strep infections. Inevitably what happens with these people feeling always tired is that something has got to give. Usually what gives ends up being the patient's spirit. Their desire to live life fully dwindles until they become a shell of their former selves. Sometimes it gets to the point where their own family members don't recognize the personality of their ill relatives anymore because they've become so withdrawn.