A sleep disorder is any condition that affects a person's ability to sleep or causes that person to have fatigue throughout the day. Most people with these conditions seek treatment after suffering from symptoms for an extended period of time. While many sleep disorders are habitual or behavioral in nature, there are medical causes for these conditions which can be treated.

Narcolepsy

Narcolepsy is a sleep disorder which causes afflicted individuals to experience sudden fatigue and "sleep attacks". During these "sleep attacks", a narcoleptic individual will sleep for a brief period of time and wake up feeling rested and refreshed. This sleep disorder can be disruptive as it can affect how a person carries out daily tasks especially if that person drives or works with heavy machinery.

Bruxism

Bruxism is a condition in which a person while clench his or her jaw while asleep and begin grinding his or her teeth. The most common cause of this condition is stress, though other factors can lead to a person grinding teeth at night. Bruxism, if moderate to severe, can lead to other health complications including damaged teeth, chronic pain and pain in the ears as a result of the tension in one's jaw.

Sleep Apnea

Sleep apnea is a condition in which a person is not able to breathe properly while asleep. Whether due to an internal obstruction or a signal problem between the brain and muscles, a person diagnosed with sleep apnea will have significant gaps between each breath which reduces oxygen levels in the body. While most cases are mild, moderate to severe cases can lead to health complications and detrimental effects on the brain.

Somnambulism (Sleepwalking)

Sleepwalking, or somnambulism is a sleep disorder in which a person will rise from bed during the third or fourth stages of the sleep cycle. As these are lighter periods of sleep, the person diagnosed with somnambulism will often perform simple tasks and roam about his or her home for a brief period of time. Though most common in young children, a number of adults have this sleep disorder throughout their lives.

Sleep Paralysis

Sleep paralysis is a condition that affects virtually everyone at least once in a person's life. As a person wakes from rest, he or she may be immobile for a brief period of time, whether a few seconds up to a few minutes. This is due to losing muscle tone during rest, though the person is not harmed and will soon be able to move. Some people who have sleep paralysis do not notice its effects due to its brief effects.

Shift Work Sleep Disorder

Shift work sleep disorder is a condition that affects people with rotating or changing work schedules. By having a changing schedule that does not allow sleep at a regular time each night, an individual will often experience fatigue and other symptoms when he or she is supposed to be working. By reducing the amount of changes in one's schedule and sleeping a regular time, one can rid him or herself of shift work sleep disorder.

Desynchronosis (Jet Lag)

Jet lag, also known as desynchronosis, is a condition that affects people who travel to different times zones rapidly and find it difficult to adjust to the new environment. The person's sleeping and eating patterns are thrown off causing fatigue and other mild issues. Physicians recommend that people attempt to eat and sleep as though they reside in the new location to help counteract the effects of jet lag on the body.

Nocturia

Nocturia is a sleep disorder that causes people to wake up during the night due to a need to urinate. Unlike enuresis (bed wetting), the person that is diagnosed with nocturia is awakened by the need to relieve him or herself. This sleep disorder is common in people who drink a large amount of liquid in the hours before going to bed. Reducing liquid intake before bedtime or the use of a diuretic during the day can relieve this sleep disorder.

Delayed Sleep Phase Syndrome

Delayed sleep phase syndrome is a chronic sleep disorder that causes people to sleep at a much later time than desired. People diagnosed with this sleep disorder sleep at the same time every night, but are often fatigued throughout the work or school day due to insufficient rest. There are treatments available for delayed sleep phase syndrome, whether through medication or through behavioral adjustments to sleep at a normal time.