Sleep disorders cause significant problems to public health. With more than 90 recognized sleep disorders and counting, science is confirming the importance of restorative sleep. These disorders are also proving to have a negative economic impact with nearly 68 billion dollars of lost work productivity annually.
Amazingly, about 75% of the US population has some sort of sleep deficiency. In terms of healthcare, sleep medicine is still a relatively new field of medicine with countless studies being conducted to better diagnose and treat people with the many different types of sleep disorders.
Obstructive Sleep Apnea (OSA) is the most recognizable and diagnosed of all sleep disorders.
About 18-20 million Americans have OSA, 4% of the male population and 2% of the female population. When adding a cardiovascular component, those numbers are estimated to reach nearly 40 million undiagnosed people.
OSA is a partial or complete closure of the airway during sleep. As the airway begins to collapse, the soft pallet will vibrate causing the patient to snore. When the airway becomes 100% closed, the patient experiences what is called an Apnea. Apnea means, the cessation of breath. In moderate to severe cases, this obstruction of breath happens several times throughout the night causing many serious physiologic responses.
OSA left undiagnosed and untreated may lead to several co-morbidities. Including:
Central Sleep Apnea Syndrome (CSAS) is an interruption of breathing throughout the night. Unlike OSA which is the closure of the airway, CSA is the result of the brain not telling the muscles to breath. This disorder, much like OSA, can be very serious when left undiagnosed and untreated.
CSAS can happen independent of OSA or with OSA. The combination of CSAS with OSA is referred to as Mixed Sleep Apnea. CSAS is often associated with other diagnoses but there is one form of CSAS that is not associated with any other conditions and there is no known cause.
Conditions that may be associated with central sleep apnea include the following:
Cheyne–Stokes respiration is an abnormal pattern of breathing characterized by progressively deeper and sometimes faster breathing, followed by a gradual decrease that results in a temporary pause in breathing called an Apnea. This pattern repeats with each cycle usually lasting in cycles from 30 seconds to 2 minutes.
Cheyne-Stokes is usually present in patients with heart failure, patients with low sodium levels in their blood, and individuals suffering from a stroke, traumatic brain injury and brain tumors. It can also occur in normally healthy people at high altitudes during sleep.
Periodic Limb Movement Disorder is typically characterized as a neurologic disorder causing the limbs to move involuntarily during sleep. These movements are usually a periodic cramping and jerking of the legs during sleep occurring about every 20-40 seconds and causing the patient to have disrupted sleep. The primary cause of PLMD is unknown.
Secondary causes of PLMD are:
Restless Leg Syndrome (RLS) is often associated with PLMD but is not the same. RLS is a disorder of part of the nervous system and is estimated to affect about 10-15% of the population.
RLS causes the patient to have the urge to move their limbs. This result is the inability to get comfortable enough to fall asleep. This movement can affect the patients arms and legs. Usual complaints of RLS are a feeling of being itchy, an electrical stimulation sensation, a feeling of “pins and needles” or a creepy, crawling sensation.
RLS effects male and females with more complaints from females. Middle aged and older patients are more severely affected by this disorder. Most cases of RLS have no known cause but it is suspected to be a genetic disorder. About 50% of people that have RLS have a family member also affected by the disorder.
Some causes of RLS, or factors that make the condition worse include:
Narcolepsy is characterized as a neurologic disorder affecting a person’s ability to stay awake. People with narcolepsy experience extreme daytime sleepiness and have intermittent and uncontrollable episodes of falling asleep during the daytime.
Normal sleep patterns include early stages of sleep followed by deeper sleep and ultimately Rapid Eye Movement (REM) sleep. This pattern repeats about every 90 minutes many times during sleep. People with narcolepsy experience REM sleep immediately in the sleep cycle and periodically during the day.
The cause of narcolepsy is unknown but scientists are making progress linking narcolepsy to a gene that releases chemicals in the brain that may signal sleep and wake cycles. People with narcolepsy are usually between the ages of 15-25 but the disorder can occur at any age.
Insomnia- Insomnia is a serious sleep disorder affecting about 30% of the population with many causes. People with insomnia have difficulty going to sleep or staying asleep.
There are two types of Insomnia, primary and secondary. Primary insomnia is characterized by a person’s inability to fall asleep absent of any medical cause. Secondary insomnia is the result of some medical condition like, asthma, depression, heartburn or cancer to name few.
Insomnia is classified as acute or chronic. Acute cases of insomnia can last one night to a few days. It is usually caused by a recent stressful event such as, change of a job, loss of a loved one, divorce, certain medications for blood pressure, asthma, colds and depression. Another cause is a person’s sleep environment. In instances specific to sleep environment; temperature, noise and light can negatively affect the persons ability to fall and stay asleep.
Chronic insomnia is defined by a person’s inability to sleep three days a week for a month or longer. The chief cause of chronic insomnia is usually depression and anxiety. Other causes include, chronic pain and stress.
Snoring- Snoring is a common problem that usually occurs more in men then woman. Interestingly, everyone that has obstructive sleep apnea snores but not everyone who snores has obstructive sleep apnea.
Snoring is usually associated with a load noise as the throat and tongue muscles relax during deep sleep. It can also be the result of the relaxing of the soft pallet and uvula This collapsing of the airway is mostly caused from being overweight but not always as there can be anatomical abnormalities such as narrower than a normal airway.
It is estimated that about 30%-50% of the US population snore and snoring usually gets worse with age. New clinical studies show that snoring without instances of apneic events may also cause other physiologic problems like Coronary Artery Disease.
Other causes of snoring can be related to an obstructed nasal airway. People with acute or chronic sinus problems can experience snoring as well as those with a deviated septum. Snoring in children is mainly caused by enlarged tonsils and/or adenoids.
Circadian Rhythm Disorders are related to interruptions in a person’s normal sleep wake cycle which is referred to a person’s Circadian Rhythm. It is more typically defined as a person’s internal clock that regulates the bodies 24 hour biological processes. The 24 hour clock revolves around the light – dark cycle.
Causes of Circadian Rhythm disorder include:
There are several types of Circadian Sleep Disorders like: