Narcolepsy vs. Chronic Fatigue Syndrome: What’s the Difference?

Medically Reviewed by Sabrina Felson, MD on July 17, 2023
3 min read

Narcolepsy and chronic fatigue syndrome (CFS) share many of the same symptoms. Doctors may mistake one for the other. Many people also have both conditions. But because the treatments for and complications of narcolepsy and CFS can differ, it’s important to get the right diagnosis.

Narcolepsy is a chronic sleep disorder that upsets your body’s sleep-wake cycles. If you have it, you’ll find it hard to stay awake for long periods of time, no matter what you’re doing. You could fall asleep while talking to someone else or while eating.

It’s unclear what causes narcolepsy, but there are a few theories:

  • Your genes could play a part.
  • You could be low on a brain chemical that helps your body know when to sleep and when to stay awake.
  • Your immune system could be attacking nerve cells in your brain by mistake.

CFS, which is now sometimes called myalgic encephalomyelitis, also makes you tired, but in a very different way. If you have CFS, you have extreme fatigue that lasts for 6 months or more and isn’t a symptom of another health issue.

Like narcolepsy, experts don’t know exactly what causes CFS. You may have it because of:

  • A virus
  • A problem with your immune system
  • Imbalanced hormones
  • Physical or mental trauma

Anyone can have one or both of these conditions. You’re more likely to have CFS if you’re a woman and slightly more likely to have narcolepsy if you’re a man.

CFS and narcolepsy share symptoms like:

  • Feeling very tired during the day
  • Trouble with focus
  • Not feeling refreshed after a good night’s sleep
  • Trouble falling asleep
  • Waking up a lot during the night

They each also have unique symptoms.

For instance, if you have narcolepsy, you can have:

  • Sudden “sleep attacks” that happen anytime
  • Hallucinations (seeing things that aren’t there)
  • Short periods in which some or all your muscles weaken
  • Sleep paralysis (inability to move when you fall asleep or as you wake up)
  • Nightmares

CFS has unique symptoms that may include:

If left untreated, both narcolepsy and CFS can impact your daily life. You may stop doing activities you enjoy or find it hard to work. Over time, you could start to withdraw from others and become depressed.

Narcolepsy can also raise your risk of hurting yourself or others. For instance, you could fall asleep while driving a car.

Because CFS and narcolepsy are so alike, doctors may not be able to make a diagnosis simply by hearing about your symptoms. Some sleep tests can confirm if you have narcolepsy, but no single test can tell if you have CFS. Your doctor will have to do blood and urine tests to rule out other conditions first.

Neither narcolepsy nor CFS has a cure, but different treatments can help you manage your symptoms. For instance, narcolepsy medications can help reduce the number of sleep attacks you have. They can also prevent loss of muscle control.

If you have CFS, your doctor may suggest over-the-counter products or prescribe drugs to help with issues like joint and muscle pain, dizziness, and depression.

Dealing with narcolepsy, CFS, or both conditions can be a challenge. Your doctor can advise you on daily lifestyle changes and ways to manage your stress that will help as well.