Research shows that sleep allows both the brain and body to slow down and engage in processes of recovery, promoting better physical and mental performance the next day and over the long-term. If your sleep is persistently disrupted, then these recovery processes can become short-circuited and have a negative effect on your concentration, energy levels, and hormones such as melatonin, cortisol [stress response hormone], growth hormones, and leptin and grehlin [hormones that regulate metabolism]. In short, poor sleep can set you up for impaired cognition as well as hormone-induced cravings for high sugar carbohydrate dense foods that will further decrease cognitive efficacy.
Sleeping patterns can also influence the cardiovascular and immune systems, so it can be potentially dangerous for patients to go untreated if they do have any kind of sleep disorder or disturbance. Another really dangerous side effect of severely impaired sleep is that you may also be so tired during the day that you are at risk of spontaneously falling asleep. It's a dangerous risk, especially when driving, which is why many long-distance drivers may require clearance for work.
Severe sleep disorders include Obstructive Sleep Apnoea (where breathing repeatedly stops and starts, depriving the brain of critical oxygen) and narcolepsy (overwhelming daytime drowsiness and sudden attacks of sleep). There are also circadian rhythm sleep disorders that can occur with shift workers, hypersomnolence (when a person feels excessive tiredness even after a full night’s sleep), periodic limb movement disorder (repetitive cramping or jerking of the legs during sleep), and REM behaviour disorder (physically acting out vivid dreams with vocal sounds and sudden arm and leg movements during REM sleep).
"Sleep disorders can often be insidious, and when treated effectively, patients always report that they never knew they could feel so good after a good night's sleep!"
JCU Graduate Laura Mariott
Even insomnia can have some serious effects as people may not be progressing through enough sleep cycles to get proper rest, leading to daytime sleepiness as well as negative effects on mood and thinking. Sleep deprivation, which can often occur with insomnia, can also result in what we call a ‘REM sleep rebound’, meaning that you may spend a disproportionate amount of time in REM sleep which can cause too much brain activity, and in turn, leave you feeling irritable with anxiety and depression likely to be heightened. REM sleep should take up between 20 to 25 percent of total sleep in healthy adults, which means on average, we should be spending about two hours per night dreaming.