I have been having this feeling of dizziness. I am working IT company doing night shift. I have been having this feeling of dizziness from past few days. Last friday I felt like I almost fainted but regained consciousness after standing. I feel like fullness in backside of my head. I start shivering and feel like I am about to faint. I feel little better when I walk in open air but starts again when I go back to the floor of my office which is on 4th floor. Not sure if its vertigo, or some internal head injury or something else.