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Chronic Fatigue Syndrome vs. Narcolepsy: How to Tell the Difference

Both narcolepsy and chronic fatigue syndrome change how you sleep. Here are the similarities and differences between the two conditions.

Taylor Leamey Senior Writer
Taylor Leamey writes about all things wellness, specializing in mental health, sleep and nutrition coverage. She has invested hundreds of hours into studying and researching sleep and holds a Certified Sleep Science Coach certification from the Spencer Institute. Not to mention the years she spent studying mental health fundamentals while earning her bachelor's degrees in both Psychology and Sociology. She is also a Certified Stress Management Coach.
Expertise Bachelor of Science, Psychology and Sociology Credentials
  • Certified Sleep Science Coach, Certified Stress Management Coach
Taylor Leamey
5 min read
Tired woman in her pajamas leaning on her kitchen counter.
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We've all had points in life when we have no energy. Sometimes it's so bad you might wonder, am I just sleep-deprived, or is something more serious going on? 

Several disorders impact someone's energy levels. Chronic fatigue syndrome and narcolepsy are two that are often confused with each other. Both cause a person to be exhausted, though the source of the sleep disturbances is different. It's important to know which one you're living with so you can address your symptoms and manage your condition. 

What is chronic fatigue syndrome? 

Everyone knows what it's like to be fatigued: you have no energy, concentrating is tough and you struggle to do everyday tasks because of it. Normal fatigue is something anyone can experience, but when things extend past regular bouts of fatigue, it becomes something else called chronic fatigue syndrome

Chronic fatigue syndrome, or myalgic encephalomyelitis, is a nervous system disorder that results in extreme fatigue, pain and disturbed sleep. The effects get worse when someone is active. According to the Institute of Medicine of the National Academies, the five main symptoms needed to diagnose chronic fatigue syndrome are: 

  • Extreme fatigue that makes it harder to do daily tasks
  • Post-exertional malaise (symptoms increasing after physical, mental or emotional exertion)
  • Cognitive impairment 
  • Unrefreshing sleep
  • Orthostatic intolerance (symptoms increasing when someone stands up)

Symptoms must be present for more than six months to be diagnosed with chronic fatigue syndrome. Other symptoms like muscle pain, headaches and dizziness can also be present. 

Experts don't know the cause of chronic fatigue syndrome. Per the Centers for Disease Control and Prevention, potential causes may be immune system changes, infections, body chemistry changes or genetics. Chronic fatigue syndrome is often confused with other conditions because many symptoms overlap. The most common is narcolepsy. 

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What is narcolepsy?

Narcolepsy differs from fatigue because it's a chronic neurological disorder that compromises your brain's sleep/wake control. Your brain can't always choose when you are asleep or awake. This results in falling asleep without warning. It's particularly dangerous if it happens while doing everyday activities like walking, driving or eating. Sudden sleep attacks can happen multiple times daily, lasting from a few seconds to hours.  

There are two categories of narcolepsy: type 1 and type 2. The difference is that type 1 narcolepsy has cataplexy, the sudden loss of muscle tone, while type 2 does not. Despite the typical depiction of narcolepsy, it's not only excessive daytime sleepiness. Those with narcolepsy also experience uneven and interrupted sleep patterns at night. If left untreated, it can significantly impact your ability to function in everyday life. 

What are the main symptoms of narcolepsy? 

According to the National Organization for Rare Disorders, up to 0.16% of people worldwide have narcolepsy. So it's not a common condition. However, with any disorder, knowing what the symptoms are can help you anticipate and cope if you live with narcolepsy. The symptoms of narcolepsy are as follows: 

  • Excessive daytime sleepiness
  • Sleep paralysis 
  • Disrupted sleep at night
  • Sudden loss of muscle control
  • Hypnagogic hallucinations (brief hallucinations while you fall asleep)

Like chronic fatigue syndrome, the exact cause of narcolepsy is unknown. However, there is research suggesting that the cause of type 1 narcolepsy (with cataplexy) is because of a low level of hypocretin, the neuropeptide involved in wakefulness. Hypocretin is made in the hypothalamus, which experiences cell death with type 1 narcolepsy. Factors that are suspected to work together to contribute to low hypocretin levels are autoimmune disorders and genetics. Though rare, narcolepsy can result after a traumatic brain injury. This is called secondary narcolepsy

Chronic fatigue syndrome and narcolepsy can seem similar on the surface because of the fatigue and sleepiness that defines the conditions. However, there are significant differences between the two.

How are chronic fatigue syndrome and narcolepsy different?


While there is overlap in how narcolepsy and chronic fatigue syndrome appear, they are different conditions marked by unique symptoms and impacts. 

Narcolepsy is a neurological disorder that compromises someone's ability to control whether they are awake or asleep. A person with narcolepsy cannot always choose if they are going to sleep or not.

Chronic fatigue syndrome is a nervous system disorder that leaves one with no energy. It doesn't affect someone's ability to choose to go to sleep. 

Young woman sleeping on her desk in front of her computer.
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Someone with chronic fatigue syndrome will not receive the same treatment as someone with narcolepsy. 

Cognitive behavioral therapy, energy treatment and over-the-counter painkillers are standard treatment options for managing symptoms associated with chronic fatigue syndrome. Dietary supplements to boost your nutrition may also be recommended.

There is no cure for narcolepsy, though it does respond to treatment. Popular treatment options include behavioral therapy, medications and nap therapy. Various types of medications can treat narcolepsy. Modafinil is an FDA-approved stimulant drug that treats excessive daytime sleepiness. There are also two classes of antidepressants -- selective serotonin reuptake inhibitors and tricyclic antidepressants -- that can help treat cataplexy and suppress hypnagogic hallucinations, per the National Sleep Foundation. 

Lifestyle changes for narcolepsy can also help someone manage their condition. Establishing a bedtime routine and avoiding caffeine or alcohol before bed can help minimize nighttime sleep disruptions. 


Our bodies naturally progress through the sleep cycle, which comprises four stages: three NREM and one REM. People with narcolepsy do not slowly move through the stages of sleep as the average person does. Instead, they jump to REM sleep quickly, within 15 minutes of falling asleep. Even though those with chronic fatigue syndrome often get poor sleep, they progress through the sleep stages.

Another difference between the two conditions is that those with chronic fatigue syndrome typically don't feel well-rested after sleep. After a narcoleptic sleep event, someone may feel refreshed.

Too long; didn't read?

Narcolepsy and chronic fatigue syndrome are two diagnosable medical conditions. And while overlapping symptoms can make them seem similar, they are significantly different based on their treatment and impact. 

Both conditions cause a person to be extremely tired and impact their sleep quality. There is no cure for either, but both are treatable with help. Speak with your doctor if you suspect you have narcolepsy or chronic fatigue syndrome. 

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.