1. Simple decisions stump you.
Not only do you have trouble making even the simplest decisions--such as what to make for dinner or which TV show to watch--but also you will take more risks in order to maximize results and have difficulty adjusting to changes.
2. You're still hungry after eating all day.
When you don't get enough sleep, your body physically rebels. Blood sugar levels can be disrupted, which also causes a disruption in two appetite-controlling hormones: leptin, a hormone that curbs your appetite is decreased, while ghrelin, a hormone that stimulates your appetite, is increased. Translation: You eat more. A lot more. Not only that, because your body is seeking a quick pick-me-up, you will crave foods made of simple carbohydrates and sugars.
3. You keep coming down with colds.
People who are not sleeping enough are more vulnerable to infections and have a weaker immune system than those who are well rested.
4. Weird things make you cry.
If a song on your iPod or a sappy TV commercial can bring you to tears, it's probably not PMS. Too little sleep can leave you emotionally volatile and unable to temper your emotions. You feel sad because a tired brain stores negative memories better than positive or neutral memories.
5. You've become a klutz.
Trip much? Drop things? There is ample scientific evidence that those who are sleep deprived have slower and less precise motor skills, possibly because being sleepy throws off your balance and depth perception.