Factors that can affect sleep: CAFFEINE, NICOTINE, MEALTIME, BEDTIME, STRESS. Caffeine won't naturally make you more awake, it blocks and steals the function of your bodies natural Adenosine uptake. If you use caffeine don't use it beyond 6-8 AM. [spoiler]Caffeine rush may feel instant and the energize boost may last an hour but then you will get tired after and crave more, caffeine doesn't leave the body for like 14-18 hours, hence why it can cause insomnia and sleeplessness if used throughout the day in large and multiple quantities. [/spoiler] Don't use Nicotine, its a toxin that acts like a drug and while it might cause a smooth calming feel it drastically affects the body and causes increased heart rate amongst other side effects you may not initially notice. Sure, Nicotine and Caffeine can keep you [i]awake[/i] and alert at work or whatever you are doing, but it does have a toll on your body and mind. Other things that can throw off sleep is not following a set time for bed or meals. Meals because energy increase at random times, and not having a set sleep schedule can throw off your bodies natural circadian rhythm. Too much stress can cause anxiety and sleeplessness, for more info on sleep, stress, and diet one should refer to a professional.