Narcolepsy is a neurological sleep disorder whose primary symptom is excessive daytime sleepiness (EDS). Type 1 narcolepsy also involves cataplexy, a sudden, temporary loss of muscle tone. Cataplexy is often triggered by strong emotions. People with type 2 narcolepsy do not experience cataplexy.

Sleep apnea is a condition that causes a person to stop breathing intermittently as they sleep. The Greek word “apnea” means “without breath.” Sleep apnea is also a sleep disorder and can be considered a breathing disorder. Obstructive sleep apnea (OSA), when the throat closes during sleep, is the most common of three types of sleep apnea. The other types of sleep apnea are central sleep apnea, when the brain fails to send a signal to breathe, and mixed sleep apnea, which is a combination of the other two types.

What Are the Differences Between Narcolepsy and Sleep Apnea?

Unlike narcolepsy, obstructive sleep apnea is not a neurological condition. However, both conditions make it difficult to stay awake and alert during the day.

It is possible to have both narcolepsy and sleep apnea. In fact, people with narcolepsy are at a higher risk of having other sleep disorders, including restless legs syndrome, insomnia, and sleep apnea. A study of 133 people with narcolepsy found 33 participants also had sleep apnea. Data suggests between 15 percent and 20 percent of people with narcolepsy also have restless legs syndrome.

Symptoms of Narcolepsy and Sleep Apnea

Excessive daytime sleepiness is one of the primary symptoms of both narcolepsy and obstructive sleep apnea. EDS makes maintaining wakefulness during the day difficult for people with sleep apnea and almost impossible for people with narcolepsy.

Narcolepsy

Excessive daytime sleepiness is a defining symptom of narcolepsy. This form of hypersomnia is so severe in people with narcolepsy, they often struggle to stay awake during the day. Other narcolepsy symptoms can include cataplexy, sleep paralysis, insomnia, and hypnagogic hallucinations (hallucinations when falling asleep). Symptoms of narcolepsy can develop at any time, but often develop in adolescence.

Sleep Apnea

Sleep apnea is a potentially serious disorder because it interrupts a person’s breathing while they sleep. These breathing interruptions can happen as many as hundreds of times throughout the night. A person can stop breathing for a minute or longer, but be unaware of any issues because they never wake fully. Other symptoms of obstructive sleep apnea include morning headaches, dry mouth upon awakening, loud snoring, and heavy sweating through the night.

Diagnosing Sleep Apnea and Narcolepsy

Difficulty staying awake during the day is often what brings people to their doctor. Because sleep apnea symptoms happen during sleep, it's usually another person who witnesses the characteristic gasping and breathing interruptions.

To diagnose both sleep apnea and narcolepsy, a doctor will usually take a detailed report of your sleep and health history and conduct a thorough physical exam. They may order a sleep study and various other tests. They may also ask you to track your sleep habits in a sleep diary.

A diagnosis of narcolepsy is often made after a health care provider rules out everything else that might be the root cause of excessive daytime sleepiness. One problem arising from the frequent co-occurrence of sleep apnea and narcolepsy is the delayed diagnosis of narcolepsy. Sometimes, when an OSA diagnosis is made, doctors may assume it's the sole cause of EDS and not look for other contributing causes.

Tests used to diagnose narcolepsy and sleep apnea may include:

• Polysomnography — A polysomnogram, or a sleep study, is an overnight test in a sleep lab that measures a person’s brain waves, breathing, heart rate, and body movements as they cycle in and out of sleep.
• Multiple sleep latency test — An MSLT, also conducted at a sleep clinic, measures daytime sleepiness. It can also rule out other sleep disorders.
• Swiss Narcolepsy Scale — Doctors may use the SNS to determine the presence of narcolepsy with cataplexy.
• Actigraph — An actigraph is a device that tracks activity and rest periods throughout the day. It can be useful in diagnosing narcolepsy, as it measures daytime sleepiness and sleep attacks.
• Lumbar puncture — A lumbar puncture is a procedure in which a needle is used to extract spinal fluid for analysis. It may show low levels of hypocretin if a person has narcolepsy.
• Home sleep apnea testing — Home sleep apnea testing involves a device that measures airflow, breathing patterns, and the amount of oxygen in a person's blood. It may also track the amount of limb movement and the level of snoring during sleep.

What Causes Narcolepsy and Sleep Apnea?

More research is required to understand the exact cause of narcolepsy. It is believed to be a complex combination of genes and triggering environmental factors. In contrast, the cause of obstructive sleep apnea is usually physiological. This can make OSA easier to identify and treat than narcolepsy.

Narcolepsy Causes

Narcolepsy is linked to low levels of hypocretin. Hypocretin is a neurotransmitter that encourages wakefulness and prevents your brain from entering REM sleep. Low hypocretin levels lead to poor sleep quality and quantity. Some people with narcolepsy have normal hypocretin levels.

A combination of genetic, autoimmune, and environmental factors increase a person’s risk for narcolepsy. Sometimes, narcolepsy may occur after a person has an infection of the upper respiratory tract. In rare cases, narcolepsy can develop as a result of head injury, sarcoidosis, stroke, or tumor.

Sleep Apnea Causes

Obstructive sleep apnea occurs when the muscles in the back of the throat relax too much, block the air passageways, and disrupt normal breathing. Specifically, the muscles that control the roof of your mouth (soft palate), tongue, tonsils, and uvula. In central sleep apnea, the airways stay open, but the brain does not signal the body to take a breath. In mixed sleep apnea, a combination of brain and airway issues occur. In all three types, a person may wake partially when breathing stops, over and over throughout the night.

Prevalence of Narcolepsy and Sleep Apnea

Narcolepsy is rare in the general population. Sleep apnea, on the other hand, is pretty common.

Who Gets Narcolepsy?

Narcolepsy affects about 1 in 2,000 to 3,000 people. However, the condition is thought to be underdiagnosed — especially in children — meaning the prevalence of narcolepsy is likely higher.

Narcolepsy affects males and females equally. Disease onset can occur at any age. Research indicates that narcolepsy is more likely to develop at about 15 years old and around 36 years of age.

Who Gets Sleep Apnea?

More than 22 million people live with sleep apnea in the United States. Sleep apnea is more prevalent among men than women. African-American and Latino men in particular experience higher rates of sleep apnea. Sleep apnea can develop at any age, but is more commonly seen in people over the age of 40 and those who are overweight.

How Are Narcolepsy and Sleep Apnea Treated?

Currently, there is no cure for narcolepsy. However, there are treatment options, and the condition is a manageable one. Sleep apnea can often be cured. Treatment for sleep apnea is usually dependent upon what is causing the condition.

Narcolepsy Treatments

Drugs and behavior changes are used to manage narcolepsy and lessen the impact of its symptoms. Medicines used to treat narcolepsy often include stimulants. Provigil (modafinil) is approved by the U.S. Food and Drug Administration (FDA) to treat daytime sleepiness. Xyrem (sodium oxybate) is approved to treat daytime sleepiness and cataplexy. There are also other recently approved medications to help manage daytime sleepiness and cataplexy. Sometimes sedatives are prescribed to improve nighttime sleep.

Behavior changes, such as exercising regularly and taking strategically scheduled naps, may improve nighttime sleep. Learn more about narcolepsy treatment options.

Sleep Apnea Treatments

Left untreated, sleep apnea can lead to serious, life-shortening medical conditions. OSA increases the risk of heart problems. Severe sleep apnea can even cause brain damage.

There are several treatment options for sleep apnea. Some are less invasive than others.

• Continuous positive airway pressure (CPAP) — A CPAP device is usually the go-to treatment for OSA. It gently blows air into a person's airway to prevent or reduce airway blockage.
• Oral appliances — These are designed to shift the position of the jaw to help keep the airway open. Over 100 oral devices are FDA approved for sleep apnea.
• Surgery — Surgery is sometimes used, depending on where the airway obstruction occurs.
• Lifestyle and behavior changes — These might include losing weight, sleeping in a different position, or not drinking alcohol before bed.

If you are experiencing excessive sleepiness during the day or any of the other symptoms mentioned in this article, talk to your doctor. Sleep apnea is curable, and there are many treatments to help manage narcolepsy symptoms.

Do you have narcolepsy or sleep apnea or both? What was your diagnostic process like? How do you manage daytime sleepiness? Comment below and or start a conversation on MyNarcolepsyTeam.