Psychological side effects include irritability, aggression, moodiness, confusion, disorientation, stress, anxiety, paranoia, exhaustion, delusions, hallucinations and a lack of reasoning, and impairment of concentration, memory and emotional control.
Physical side effects include trembling hands, drooping eyelids, staring and inability to focus eyes, increased pain sensitivity, headaches, decreased production of growth hormone, decreased metabolism, decreased muscle strength, decreased fine-motor function, lowered immunity to illness and increased appetite and weight.
Moderate sleep loss mainly affects the ability to perform simple, routine tasks or boring tasks. There is relatively little impairment on interesting or complex tasks. People derived of sleep also experience microsleeps, which are short periods of sleep where the individual appears to be awake.