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HCM Sleep Lab

Common Sleep Disorders

Sleep Apnea and Snoring

Everyone snores occasionally. However, loud and disruptive snoring can be a symptom of a more serious problem called sleep apnea. Sleep apnea is caused by interruptions in breathing during sleep causing frequent awakenings and restless sleep. The sufferer may often exhibit a certain pattern: snoring… a silence… and then choking/gasping/snorting and leg kicking. Although the sufferer wakens frequently, they may not be aware of how often they are awakening and the interruptions in their breathing. Their restless nights can often lead to fatigue and excessive sleepiness during the day as well as difficulty focusing, short term memory loss and mood swings. Left untreated, sleep apnea can lead to serious health problems such as high blood pressure, heart disease, stroke and diabetes.

Symptoms may include:

  • Loud snoring
  • Witnessed apnea
  • Excessive daytime sleepiness
  • Excessive daytime fatigue
  • Nocturnal choking/gasping
  • Morning headaches
  • Awakening frequently to urinate
  • Irritability, moodiness, depression
  • Hypertension
  • Difficulty focusing / short term memory loss


Narcolepsy is a chronic sleep disorder characterized by overwhelming daytime drowsiness and sudden attacks of sleep. People with narcolepsy often find it difficult to stay awake for long periods of time, regardless of the circumstances.

Related signs and symptoms include:

  • Cataplexy – an episode in which all muscle function is weakened or loss. These episodes are often triggered by emotions such as laughing, crying, terror, etc. and often lead to complete body collapse.
  • Sleep paralysis when falling asleep or awakening.
  • Dream-like hallucinations when falling asleep.
  • Excessive daytime fatigue and sleepiness.


Insomnia is defined as an inability to initiate sleep and maintain sleep for a reasonable period of time. Sufferers of insomnia typically experience “racing thoughts” and the inability to “turn off the brain”. Symptoms of insomnia often are the same as other sleep disorders; therefore, finding the underlying cause is most important.

Periodic Limb Movement Disorder (PLMD) and “restless legs” syndrome

Periodic limb movement disorder (PLMD) is a sleep disorder characterized by rhythmic movements of the limbs during sleep. The movements typically involve the legs, but upper extremity movements may also occur. Movements occur periodically throughout the night and can fluctuate in severity from one night to the next. These involuntary movements can lead to frequent awakenings and restless sleep. Many sufferers refer to this condition as “restless legs during the night”.

Symptoms may include:

  • Crawling sensations in legs
  • Muscle tension in legs
  • Kicking at night
  • Excessive daytimes sleepiness (EDS)