Sleep deprivation is considered a disorder itself but can develop from numerous sources. A person suffering from sleep deprivation simply does not get the amount of sleep they need to function properly. When it is long term, you will experience fatigue, daytime sleepiness, slow reaction time, clumsiness, weight gain, and other health problems. Physiological effects such as dizziness, nausea, sore muscles, headaches, irritability, and hallucinations can occur. These are not good symptoms when you fly a plane or operate some other type of transportation vehicle.