Exhaustion is first of all a completely normal feeling. If you have worked a lot or have been able to get little sleep, then you need not be surprised if you feel tired at some point. But that is not what is meant here: it is not a calm, contented tiredness, but a restless, driven exhaustion, a tension-filled emptiness.
Another difference: if you have simply done too much for a while, then a soothing night's rest, a relaxing weekend or, in a pinch, a few quiet vacation days or weeks will help.
But for patients, it's different. Neither the night sleep, nor the sick leave, nor the rest during the day somehow makes it better. They have an almost indomitable need for rest and recuperation - but that need cannot be satisfied. It seems like an evil curse: the more they rest, the more exhausted they feel. We have patients who, after months or years of rest, can practically only lie down. Even sitting overwhelms them after a short time, not to mention standing or other movement.
What kind of complaint is this? What is to be done?