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Understanding Sleep Problems -- The Basics


What Causes Sleep Disorders?


Insomnia may be temporary and stem from a simple cause, such as jet lag. Short-term insomnia may also be caused by an illness, a stressful event, or drinking too much coffee, for example. Many medications have insomnia as a side effect.

Long-term insomnia may be caused by stress, depression, or anxiety. People can also become conditioned to insomnia: They associate bedtime with difficulty, expect to have trouble sleeping (and thus do), and become irritable (which can cause more insomnia). This cycle can be maintained for several years.

Circadian rhythm disorders are an important but less common cause of insomnia. People who abuse alcohol or drugs often suffer from insomnia.

Snoring and Sleep Apnea

When you fall asleep, many muscles in your body relax. If muscles in the throat relax too much, your breathing may be blocked and you may snore. Sometimes, snoring is caused by allergies, asthma, or nasal deformities that make breathing difficult.

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.

Drops in blood oxygen during sleep -- once thought to be the cause of waking up due to obstructive sleep apnea -- may or may not be present. Most likely, awakening occurs with the body's increased effort required to overcome the obstruction of the airway.

Drinking alcohol can make obstructive sleep apnea worse because it relaxes muscles that maintain an open airway.

A rare form of sleep apnea called central sleep apnea occurs when signals from the brain to your muscles decrease or stop for a short time. You may not snore if you have central sleep apnea.

Pregnancy and Sleep

Fatigue during the first trimester of pregnancy is likely caused by changing levels of hormones, such as progesterone. Toward the end of pregnancy, some women find it difficult to sleep because of the uncomfortable size of their abdomen. Some women are too excited, anxious, or worried about becoming mothers to sleep well. Other women who are pregnant complain that vivid dreams prevent them from getting restful sleep. Sleep apnea, especially if it's severe and causes your blood oxygen level to drop during sleep, is a risk to the fetus.

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