Causes of Sleep Disorders
What are the causes of some of the most common sleep disorders? Although the answer is often unknown, we are slowly learning what might contribute to the various disruptions in sleep.
Snoring and Sleep Apnea
Snoring is simply a sound produced by the vibration of soft tissues in the nose, throat, and mouth. It occurs nearly universally. However, it may also be associated with conditions that narrow the upper airway. These may include:
- obesity
- nasal congestion
- malformation of the skull or face (including abnormal jaw position or size and narrow nasal cavities)
- hypothyroidism
- acromegaly
- tonsil or adenoid enlargement
In severe cases, snoring may also coexist with complete cessation of breathing called obstructive sleep apnea. This condition is common and may be seen in those with the above abnormalities. In addition, it is more prevalent in men and older adults. Other risk factors include: heredity, smoking (which makes sleep apnea three times as common), and increased neck circumference.
Some individuals may suffer from central sleep apnea, which is a failure of the brain to stimulate breathing while one is asleep. Heart failure is the most common cause. It can also be caused by problems with the central nervous system, neuromuscular disease, or with severe abnormalities in the process of breathing. It can also occur in healthy individuals at sleep onset.
Insomnia
There are numerous potential causes of insomnia, which is the most common of the sleep disorders. These causes may include:
- stress
- poor sleep habits
- medications
- caffeine or stimulant use
- drug use
- other medical or psychiatric conditions
- idiopathic or unrecognized causes
Parasomnias
Parasomnias are undesirable actions or experiences which occur "around sleep." They may appear purposeful, but the individual typically has no conscious awareness or recollection of the events. These may include sleepwalking, sleep terrors, sleep paralysis, and REM sleep behavior disorders (in which a person acts out his or her dreams). In general, the cause of these disorders is not entirely understood but some potential causes include medications, drug use, and other medical or psychiatric conditions. For example, REM sleep behavior disorder seems to be associated with Parkinson's disease, but the mechanism is not understood.
Sleep Paralysis
Sleep paralysis is believed to be a problem with the regulation of REM sleep. During this phase of sleep, the body is kept relaxed so that dreams are not acted out. If this relaxation (or atonia) occurs while the person is awake, it can cause temporary paralysis. This may be experienced when a REM period is disrupted. How this occurs is not fully understood at this time, but it is relatively common.
