What is happening physiologically during sleep deprivation that leads to feeling ao awful? Is it normal to feel particularly terrible like you have the flu if you have say 4 hours of sleep? Sometimes I think that maybe I feel worse than others when i dont sleep and was curious what your thoughts on tge matter are. I am like a completely differeng person when even moderately sleep deprived amd was wondering if anything pathological is happening there. In contrast, when I get a normal amount of sleep ie, 7 to 9 hours I feel awesome.
There are a whole lot of things going on physiologically, most of which are beyond the scope of what we can realistically get into via the forum here.
It is common to feel poorly when you get significantly less sleep than your individual needs, yes. I understand that is not a terribly helpful answer, but if you feel great when you get 7-9 and poorly when you get 4, I would not interpret that as evidence of pathology.