A nocturnal movement disorder, restless leg syndrome can feel like itchiness, tingling, or prickling that makes you feel like you have to move your legs. Your legs may also move without your control while you sleep. You may or may not be aware of waking during the night, but restless leg syndrome causes sleep problems by preventing deep, restful sleep.

A systematic review states 7.6% of the general population experiences sleep paralysis at least once in their lifetime. Its prevalence among men is 15.9% while 18.9% of women experience it. When considering specific populations, 28.3% of students and 31.9% of psychiatric patients have experienced this phenomenon at least once in their lifetime. Of those psychiatric patients, 34.6% have panic disorder. Sleep paralysis in students is slightly more prevalent for those of Asian descent (39.9%) than other ethnicities (Hispanic: 34.5%, African descent: 31.4%, Caucasian 30.8%).[67]


Narcolepsy is a sleep disorder that involves excessive, uncontrollable daytime sleepiness. It is caused by a dysfunction of the brain mechanism that controls sleeping and waking. If you have narcolepsy, you may have “sleep attacks” in the middle of talking, working, or even driving. Although no cure yet exists, a combination of treatments can help control symptoms and enable you to enjoy many normal activities.
In Alzheimer's disease, in addition to cognitive decline and memory impairment, there is also significant sleep disturbances with a modified sleep architecture.[30][29] The latter may consist in sleep fragmentation, a reduction in sleep duration, insomnia, an increase daytime naping, a decreased quantity og some sleep stages and a resemblance between some sleep stages (N1 and N2).[29] More than 65% of people with Alzheimer's disease suffer from this type of sleep disturbance.[29]
Sleep dentistry (bruxism, snoring and sleep apnea), while not recognized as one of the nine dental specialties, qualifies for board-certification by the American Board of Dental Sleep Medicine (ABDSM). The resulting Diplomate status is recognized by the American Academy of Sleep Medicine (AASM), and these dentists are organized in the Academy of Dental Sleep Medicine (USA).[53] The qualified dentists collaborate with sleep physicians at accredited sleep centers and can provide oral appliance therapy and upper airway surgery to treat or manage sleep-related breathing disorders.[54]
Obstructive sleep apnea (OSA) affects around 4% of men and 2% of women in the United States.[63] In general, this disorder is more prevalent among men. However, this difference tends to diminish with age. Women experience the highest risk for OSA during pregnancy.[64] Also, they tend to report experiencing depression and insomnia in conjunction with obstructive sleep apnea.[65] In a meta-analysis of the various Asian countries, India and China present the highest prevalence of the disorder. Specifically, about 13.7% of the Indian population and 7% of Hong-Kong's population is estimated to have OSA. The two groups experience daytime OSA symptoms such as difficulties concentrating, mood swings, or high blood pressure,[66] at similar rates (prevalence of 3.5% and 3.57%, respectively).[63]
Histamine plays a role in wakefulness in the brain. An allergic reaction over produces histamine causing wakefulness and inhibiting sleep[37] Sleep problems are common in people with allergic rhinitis. A study from the N.I.H. found that sleep is dramatically impaired by allergic symptoms and that the degree of impairment is related to the severity of those symptoms [2]s[38] Treatment of allergies has also been shown to help sleep apnea.[39]
Narcolepsy is characterized by “sleep attacks” that occur during the day. This means that you will suddenly feel extremely tired and fall asleep without warning. The disorder can also cause sleep paralysis, which may make you physically unable to move right after waking up. Although narcolepsy may occur on its own, it is also associated with certain neurological disorders, such as multiple sclerosis.
Restless leg syndrome (RLS) is an overwhelming need to move the legs. This urge is sometimes accompanied by a tingling sensation in the legs. While these symptoms can occur during the day, they are most prevalent at night. RLS is often associated with certain health conditions, including ADHD and Parkinson’s disease, but the exact cause isn’t always known.
Apnea means "no airflow." Obstructive sleep apnea was thought to be a disorder primarily of overweight, older men. But abnormal breathing during sleep can affect people of any age, any weight, and either sex. Researchers now know that in many cases of sleep apnea, the obstruction in the airways is only partial. Most people with sleep apnea have a smaller-than-normal inner throat and other subtle bone and soft-tissue differences.
A nocturnal movement disorder, restless leg syndrome can feel like itchiness, tingling, or prickling that makes you feel like you have to move your legs. Your legs may also move without your control while you sleep. You may or may not be aware of waking during the night, but restless leg syndrome causes sleep problems by preventing deep, restful sleep.
Combining results from 17 studies on insomnia in China, a pooled prevalence of 15.0% is reported for the country.[60] This is considerably lower than a series of Western countries (50.5% in Poland, 37.2% in France and Italy, 27.1% in USA).[60] However, the result is consistent among other East Asian countries. Men and women residing in China experience insomnia at similar rates.[60] A separate meta-analysis focusing on this sleeping disorder in the elderly mentions that those with more than one physical or psychiatric malady experience it at a 60% higher rate than those with one condition or less. It also notes a higher prevalence of insomnia in women over the age of 50 than their male counterparts.[61]
A population susceptible to the development of sleep disorders is people who have experienced a traumatic brain injury (TBI). Because many researchers have focused on this issue, a systematic review was conducted to synthesize their findings. According to their results, TBI individuals are most disproportionately at risk for developing narcolepsy, obstructive sleep apnea, excessive daytime sleepiness, and insomnia.[20] The study's complete findings can be found in the table below:

Sleep dentistry (bruxism, snoring and sleep apnea), while not recognized as one of the nine dental specialties, qualifies for board-certification by the American Board of Dental Sleep Medicine (ABDSM). The resulting Diplomate status is recognized by the American Academy of Sleep Medicine (AASM), and these dentists are organized in the Academy of Dental Sleep Medicine (USA).[53] The qualified dentists collaborate with sleep physicians at accredited sleep centers and can provide oral appliance therapy and upper airway surgery to treat or manage sleep-related breathing disorders.[54]


What to do: This condition requires evaluation by an otolaryngologist, who can look at your nose, mouth, and throat to see what's interrupting your breathing and how to repair that process. You'll also need a sleep test in which your oxygen levels are measured. Often, the first treatment doctors will recommend is a Continuous Positive Airway Pressure (CPAP) device, a specially designed nasal mask that blows air directly into your airways. Studies have shown CPAP masks to be extremely effective in treating sleep apnea. However, many people don't like wearing them -- and, of course, it doesn't work if you don't wear it.
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