Narcolepsy vs. Obstructive Sleep Apnea: What’s the Difference?

Medically Reviewed by Sabrina Felson, MD on July 15, 2023
Written by Susan Bernstein
5 min read

Narcolepsy and obstructive sleep apnea (OSA) are both chronic sleep disorders. They have some symptoms and risk factors in common, and it’s possible to have both conditions at the same time. But they are two different conditions that require different treatments. That’s why it’s important to get the right diagnosis if you have one or both conditions.

So, what’s the difference?

This is a sleep disorder that causes you to have sudden uncontrollable “sleep attacks” during the day. It causes you to feel very sleepy and suddenly fall asleep frequently throughout the day. You fall asleep even if it’s noisy or if there’s activity around you. You find it very difficult to stay awake.

Narcolepsy can cause sudden sleepiness even when you need to stay awake for your own safety, such as while you drive or cook. You can even keep driving or working while you’re asleep and not remember what you did or said.

Frequent naps in the daytime may refresh you, but after a couple of hours, you’re tired again.

Excessive daytime sleepiness and frequently falling asleep are narcolepsy’s most common symptoms. Narcolepsy can cause the following symptoms, too.

Cataplexy. This is a sudden loss of muscle tone. You may have slurred speech or muscle weakness that causes your knees to buckle or your head to droop. Sudden emotional reactions like laughter or fear may trigger these attacks. Not everyone with narcolepsy has cataplexy.

Sleep paralysis. You can have a very short loss of the ability to move or speak when you fall asleep or just wake up.

Fast onset of REM (rapid eye movement) sleep. People who have narcolepsy enter this phase of sleep -- the one in which you dream -- much more quickly after they fall asleep than other people, even when they fall asleep in the middle of the day.

Hallucinations. You may see things that aren’t there as you are falling asleep or as you wake up.

Fragmented sleep. You may sleep in short segments at night rather than uninterrupted through the night.

Trouble falling back to sleep. After you wake up from these sleep segments, you may struggle to doze off again.

Memory problems. You may not remember what you said or did during sleepy episodes or just before you nod off.

Obstructive sleep apnea (OSA) is a breathing condition. Your airways don’t stay open while you sleep, so you can’t breathe normally. Your breathing may pause anywhere from a few times to hundreds of times each night.

OSA can happen when tissue like your adenoid glands, tonsils, or even excess body fat narrows your throat while you sleep. Your throat muscles may relax as you sleep, so your tongue rolls back and blocks your throat. You struggle to breathe, and oxygen can’t reach your lungs.

Like narcolepsy, a common symptom of OSA is excessive daytime sleepiness. You’re tired all the time, because you can’t get a good night’s sleep.

OSA symptoms include:

The most common symptom of both narcolepsy and OSA is excessive daytime sleepiness.

They also share some of the same risk factors. People with both narcolepsy and OSA are often overweight or obese. Both conditions may run in families. If any of your relatives have narcolepsy or OSA, you’re at risk for it, too.

Narcolepsy and OSA may have similar symptoms or effects on your life, too. You may:

  • Struggle to focus or concentrate during the day.
  • Nod off for short naps, even at work or in the car.
  • Have memory lapses.
  • Struggle to maintain your personal or intimate relationships.
  • Fall asleep at times when your safety depends on staying awake, like while you drive.
  • Hallucinate. These are more common in narcolepsy. But it sometimes affects people with OSA, possibly because you only sleep in very short fragments.

Narcolepsy is somewhat rare. It may affect less than 1% of people in the U.S. OSA is a common sleep disorder that affects up to 22% of men and 17% of women in the U.S.

Narcolepsy and OSA usually first appear at different ages:

  • Narcolepsy’s first symptoms usually appear in adults before they turn 30, or even in children as young as 10.
  • Obstructive sleep apnea tends to begin around age 40 or older.

Narcolepsy and OSA often have different causes and risk factors:

  • Narcolepsy may come from low levels of a brain chemical called hypocretin. This chemical regulates when you sleep and when you’re awake.
  • OSA often has mechanical causes. Some tissue blocks or narrows your throat during sleep. People with overbites, receding chins, large tonsils, a deviated septum, or polyp growths inside their nose may develop OSA. Other risk factors for OSA include things you can take steps to change, like smoking, alcohol use, or obesity.

The two conditions also affect men and women differently. Men are more likely to develop OSA than women. After menopause, women’s risk for OSA increases. Women and men get narcolepsy at the same rate, but men usually get a diagnosis earlier in life.

It’s possible to have both narcolepsy and obstructive sleep apnea. About one quarter of people who have narcolepsy also have some other sleep condition. Usually, it’s OSA.

These could be some clues that you might have both:

Obesity. You’re more likely to have both conditions if you’re obese. Low hypocretin levels in narcolepsy can slow your metabolism, which makes it harder to maintain a healthy weight.

Obesity is also a major risk factor for OSA. Excess fat around your neck or chin area can shrink your throat opening when you lie down to sleep.

Confusing symptoms. If you have OSA and narcolepsy without cataplexy, your doctor may miss the signs of narcolepsy and not realize you have both conditions.

A CPAP doesn’t help. If you get a diagnosis of OSA, your doctor will likely prescribe a continuous positive airway pressure (CPAP) machine or similar device worn while you sleep to help you breathe normally. CPAP helps most people with OSA improve quickly, sleep well, and stop snoring.

If using a CPAP doesn’t improve your daytime sleepiness, you may also have narcolepsy. Talk to your doctor. They can give you a sleep test to be sure you have the correct diagnosis.