Sleep Disorders

Sleep disorders are medical conditions that interrupt standard sleep patterns. There are at least 80 different types of sleep disorders.

Explore this page to learn about the most common types of sleep disorders, including what they are, major types associated with each of them, and the consequences of leaving them undiagnosed and untreated.

For more information about the symptoms, diagnosis, and treatment options associated with these sleep disorders, you can explore our Patients/Get Help page.

Sleep Apnea

Sleep apnea is one of the most common sleep disorders, affecting nearly one billion people worldwide.

You’re probably wondering: What even is sleep apnea? Well, sleep apnea is characterized by recurrent pauses in breathing while someone is asleep. Someone with sleep apnea can momentarily stop breathing up to 100 times per hour.

There are three types of sleep apnea:

  • Obstructive sleep apnea: Occurs when something blocks the airway, preventing you from breathing correctly. Usually, the soft tissue at the back of the throat closes during sleep.
  • Central sleep apnea: Occurs when your brain doesn’t send proper signals to the muscles to breathe.
  • Mixed sleep apnea: This is a combination of obstructive and central sleep apnea and occurs when the brain slightly wakes the sleeper to resume breathing.

Idiopathic Hypersomnia

What is hypersomnia? The term Idiopathic Hypersomnia (IH) describes a chronic condition in which someone feels excessively tired during the day—even after a whole night of sleep. Those with hypersomnia may also sleep longer than usual and continue to experience exhaustion. This disorder is commonly referred to as excessive daytime sleepiness (EDS).

There are two types of hypersomnia:

  • Primary: Occurs when no other medical conditions are present. Primary hypersomnia is a neurological condition that has no known underlying cause.
  • Secondary: This type of hypersomnia occurs secondary to—or as a symptom of—other medical conditions, medications, psychological disorders, or substances.

Those with IH usually have a hard time waking in the morning and experience grogginess and brain fog during waking hours. Because this sleep disorder can go without a diagnosis for a long time, people suffering from it may wrongfully blame themselves when they experience difficulty maintaining work, relationships, or schooling.


You may have heard of insomnia, the most common sleep-related complaint out there. With a whopping 35 percent of adults complaining of this sleep disorder, it’s easy to see why it’s the most well-known of the bunch.

What is insomnia exactly? Insomnia occurs when someone has trouble falling or staying asleep—even when they have the opportunity to get a whole night of sleep.

There are two types of insomnia:

  • Short-term, which only lasts for up to three months.
  • Chronic, which occurs at least three times per week for at least three months.

Not only does insomnia impact the quality of your sleep, but it can also negatively affect your work performance, relationship quality, decision making, mood, and even worsen other existing medical concerns. Overall, many of those who report insomnia also report a poorer quality of life.


Narcolepsy is a chronic sleep disorder that involves daytime drowsiness and unexpected attacks of sleep. Those suffering with narcolepsy usually have a hard time staying awake for extended periods of time—in any context and may fall asleep at any moment.

There are two types of narcolepsy:

  • Type 1 narcolepsy: Is accompanied by a sudden loss of muscle tone, as triggered by strong emotion
  • Type 2 narcolepsy: Occurs without a sudden loss of muscle tone

Narcolepsy can cause severe disruptions in one’s daily routine. While there is no cure for the sleep disorder, a combination of medication, lifestyle changes, and support from others can help people cope with it.

Periodic Limb Movement Disorder

Periodic limb movement disorder (PLMD) is a rare disorder that involves repetitive jerks of the legs and feet during sleep. These movements can occur every few seconds for up to an hour at a time, seriously disrupting someone’s sleep even if they don’t wake up because of it.

PLMD may manifest itself as a primary or secondary disorder. In cases of primary PLMD, the disorder appears on its own, while in secondary PLMD, it is caused by another medical condition, like diabetes, iron deficiency, caffeine, or injury.

Many individuals with PLMD have no idea they have it as movements occur as they are asleep. Because they experience many of the same symptoms associated with insomnia—such as feeling excessively tired throughout the day—most of them assume they have insomnia and do not seek further treatment.