Back in my teens I went a few times without sleep for extended periods of time. At times I used to go more than a week without sleep. Now days I can only really manage about 2 or maybe 3 days without sleep, then I collapse.
From past experience it goes something like this:
Day 1: Tired, could use a nap.
Day 2: Not tired anymore, but short tempered and irritable.
Day 3: Sporadic sensations of being drained, with irritability and higher stress levels, and now always tired.
Day 4: Full of energy, but stressed out and constantly paranoid and irrational.
Day 5: Stress, short temper, confused, mild hallucinations out the corner of the eye.
Day 6: You will now feel like the walking dead until you either join the dead or sleep. The world is in slow motion, you are stressed, worried, paranoid, and suffering mild hallucinations in general. ... (from black cats and bugs out of the corner of you eye, to objects just outside of focus becoming warped, some black spots that come and go.)
Day 7: For all other days refer to day 6.