It's been happening since a week, its been a month Since I have been to Chandigarh. I feel this pressure on the left side of my head like someone is hardly pushing or putting pressure over the left side of my head or like some shrinking sensation, it just happens on the left side. I've been working later for about 13 hrs now a days, is that the cause or anything else ? And I do sleep for about 7 - 8 hours a day.