Adolescents who experience less sleep show a decreased willingness to engage in sports activities that require effort through fine motor coordination and attention to detail.Great sleep deprivation mimics psychosis: distorted perceptions can lead to inappropriate emotional and behavioral responses.Astronauts have reported performance errors and decreased cognitive ability during periods of extended working hours and wakefulness as well as due to sleep loss caused by circadian rhythm disruption and environmental factors.One study has found that a single night of sleep deprivation may cause tachycardia, a condition in which the heartrate exceeds 100 beats per minute (in the following day).Generally, sleep deprivation may facilitate or intensify:
aching muscles
confusion, memory lapses or loss
depression
development of false memory
hypnagogic and hypnopompic hallucinations during falling asleep and waking, which are entirely normal
hand tremor
headaches
malaise
stye
periorbital puffiness, commonly known as "bags under eyes" or eye bags
increased blood pressure
increased stress hormone levels
increased risk of Type 2 diabetes
lowering of immunity, increased susceptibility to illness
increased risk of fibromyalgia
irritability
nystagmus (rapid involuntary rhythmic eye movement)
obesity
seizures
temper tantrums in children
violent behavior
yawning
mania
Sleep inertia
symptoms similar to:
attention-deficit hyperactivity disorder (ADHD)
psychosis

Assessment
Patients with sleep deprivation may present with complaints of symptoms and signs of insufficient sleep such as fatigue, sleepiness, drowsy driving, and cognitive difficulties. Sleep insufficiency can easily go unrecognized and undiagnosed unless patients are specifically asked about it by their clinicians.Several questions are critical in evaluating sleep duration and quality, as well as the cause of sleep deprivation.
The study also found that rapid eye movement sleep (REM) deprivation may alleviate clinical depression because it mimics selective serotonin reuptake inhibitors (SSRIs). This is because the natural decrease in monoamines during REM is not allowed to occur, which causes the concentration of neurotransmitters in the brain, that are depleted in clinically depressed persons, to increase. Sleep outside of the REM phase may allow enzymes to repair brain cell damage caused by free radicals. High metabolic activity while awake damages the enzymes themselves preventing efficient repair. This study observed the first evidence of brain damage in rats as a direct result of sleep deprivation. Attention and working memory
Among the possible physical consequences of sleep deprivation, deficits in attention and working memory are perhaps the most important; such lapses in mundane routines can lead to unfortunate results, from forgetting ingredients while cooking to missing a sentence while taking notes. Performing tasks that require attention appears to be correlated with number of hours of sleep received each night, declining as a function of hours of sleep deprivation. Working memory is tested by methods such as choice-reaction time tasks.The attentional lapses also extend into more critical domains in which the consequences can be life-or-death; car crashes and industrial disasters can result from inattentiveness attributable to sleep deprivation. To empirically measure the magnitude of attention deficits, researchers typically employ the psychomotor vigilance task (PVT) which requires the subject to press a button in response to a light at random intervals.