I love it when a whumpee is so weak that they:
are bedridden, much to their discomfort. They long to leave the bed, but cannot because they are too weak, and their legs shake at the thought of taking even a single step.
can't keep their eyes open. Their eyelids flutter but due to tiredness and too much light, they always close again. However, the whumpee has learned to rely on other senses, and is able to recognize the caretaker's voice or touch among a thousand others.
have to always lie down. They try to sit up, perhaps to eat something, but after a few minutes their head starts spinning and their body starts screaming because of the effort. Much to their chagrin, they have to force themselves back down or else they will likely pass out.
are not hungry. Their body can't handle even plain broth, making them queasy and dizzy. So they continue to refuse food, their only source of livelihood, and this obviously worsens their condition.
are too sensitive to touch. Their skin that seems to boil with fever, the bedsheets that rub down their limbs like sandpaper, the hair that sticks to their sweaty forehead, even the simple touch of the caretaker, a touch that is supposed to comfort them. They start to hate all these little things.
Please, feel free to add more.