Narcolepsy is a neurological condition that affects your body’s sleeping and waking cycles.

It’s estimated that between 135,000 and 200,000 people in the United States have narcolepsy. If you have it, you’ll often feel very tired during the day and may also unexpectedly fall asleep in the middle of activities. It’s also possible to experience cataplexy, which is when muscle weakness comes on suddenly.

Adrenal insufficiency is a health condition where your adrenal glands don’t make enough of certain hormones. This can lead to symptoms that are similar to those of narcolepsy, such as chronic fatigue and muscle weakness.

Another related term you may have heard of is “adrenal fatigue,” which is used to describe a mild type of adrenal insufficiency that’s supposedly brought on by chronic stress. However, adrenal fatigue isn’t a proven medical condition.

Below, we’ll explore the ins and outs of narcolepsy, adrenal insufficiency, and adrenal fatigue. Keep reading to learn more.

Adrenal fatigue is a theory that chronic stress can impact the function of the adrenal glands. The adrenal glands are found above your kidneys and make hormones like cortisol, which is important for how you respond to stress.

Supporters of the theory of adrenal fatigue believe that the buildup of stress becomes too much for your adrenal glands. Due to this, they cannot produce enough cortisol to meet the body’s demands, causing symptoms like:

  • lasting fatigue or feeling continually “run down”
  • disrupted sleep, such as difficulty falling sleep or trouble waking up
  • cravings for salt, sugar, or both

While some symptoms of adrenal fatigue are similar to those of narcolepsy, it really isn’t possible to compare the two. This is because adrenal fatigue isn’t recognized as a legitimate medical condition.

In a 2016 article, a group of endocrinologists reviewed 58 studies mentioning adrenal fatigue. Based on their review of the studies and how they were conducted, they could find no credible evidence that adrenal fatigue is an actual medical condition.

The reported symptoms of adrenal fatigue are general and could be caused by any actual health condition that needs to be treated. According to the Endocrine Society, these may include conditions like:

Adrenal insufficiency is a medical condition in which your adrenal glands don’t make enough of the hormone cortisol and, in some cases, aldosterone. There are several types of adrenal insufficiency.

Some types have to do with decreased production of hormones in the brain. These hormones eventually promote cortisol production in the adrenal glands, so when they’re in short supply, cortisol levels are lower.

Some types of narcolepsy also have to do with decreased hormone production in the brain. In this case, it’s the hormone hypocretin, also called orexin, which regulates sleeping and waking.

It’s also possible for people with narcolepsy to have other health conditions involving hormones, such as adrenal insufficiency and hypothyroidism.

Older research has also found that low levels of hypocretin in people with narcolepsy may impact other hormone pathways, such as those involved in adrenal insufficiency.

Lastly, there’s overlap in the symptoms of adrenal insufficiency and narcolepsy, such as excessive tiredness or fatigue and muscle weakness.

However, there are many important differences between adrenal insufficiency and narcolepsy as well. Let’s go over the different aspects these two conditions now.


Adrenal insufficiency

The symptoms of adrenal insufficiency typically come on slowly and can include things like:


The symptoms of narcolepsy can include:


Adrenal insufficiency

There are different types of adrenal insufficiency and each type as its own cause:

  • Primary adrenal insufficiency: Also called Addison’s disease, primary adrenal insufficiency is often caused by autoimmune activity. This is when your immune system attacks healthy tissues. It can also be caused by:
    • bleeding in the adrenal glands
    • certain genetic conditions that affect the adrenal glands
  • Secondary adrenal insufficiency: Secondary adrenal insufficiency happens when the pituitary gland in your brain doesn’t make a hormone called ACTH, which goes on to stimulate cortisol production. It can be caused by:
    • autoimmune activity
    • brain injuries or bleeding
    • infections impacting the brain
    • certain genetic conditions that affect the pituitary gland
  • Tertiary adrenal insufficiency: Tertiary adrenal insufficiency happens when the hypothalamus in your brain doesn’t make enough of a hormone called CRH, which stimulates ACTH production in the pituitary gland. It can often happen due to long-term corticosteroid use.


Similar to adrenal sufficiency, there are different types of narcolepsy. What causes each type is a little different.

People with type 1 narcolepsy, or narcolepsy with cataplexy, almost always have low levels of a hormone called hypocretin in the brain. This hormone is involved in regulating aspects of sleeping and waking.

Those with type 2 narcolepsy, or narcolepsy without cataplexy, have normal levels of hypocretin. The cause of this type of narcolepsy remains unclear.

Factors that may contribute to the development of narcolepsy in general include:

  • autoimmune activity against cells that make hypocretin
  • genetics
  • an injury, tumor, or illness that affects the part of the brain involved in sleeping and waking

Risk factors

Adrenal insufficiency

The risk factors for adrenal insufficiency can include:

  • being assigned female at birth (Addison’s disease)
  • having an injury or health condition that impacts the pituitary gland or hypothalamus
  • having certain genetic conditions that affect the function of the adrenal glands, pituitary gland, or hypothalamus
  • taking corticosteroids for long periods


You may be at an increased risk for narcolepsy if someone in your family has it. About 10% of people with type 1 narcolepsy have a close relative who reports similar symptoms.


Adrenal insufficiency

An adrenal crisis is the most serious complication of adrenal insufficiency and is life threatening. It can happen when your body needs more cortisol than it can make, typically in response to intense physical stress caused by things like:

  • an injury
  • a surgery
  • a serious illness

It’s also possible for adrenal insufficiency to lead to electrolyte imbalances like too little sodium or too much potassium.


The nature of its symptoms can mean that narcolepsy can have a large impact on a person’s quality of life. People with narcolepsy can experience significant disruptions in their daily life, including:

  • lower performance at work or in school
  • trouble with interpersonal relationships
  • difficulty maintaining employment
  • increased levels of depression or anxiety

Additionally, sleep attacks and cataplexy can happen suddenly. This can be dangerous if you’re driving or working in a job that involves operating heavy machinery.


Adrenal insufficiency

In addition to taking your medical history and doing a physical exam, a doctor can use the following tests to diagnose adrenal insufficiency:

  • Blood tests: These test for levels of the hormones cortisol and ACTH. A renin test can also be used to detect low levels of aldosterone.
  • ACTH stimulation test: For an ACTH stimulation test, you’ll be given artificial ACTH. Your cortisol levels will be measured both before and after. In people with primary adrenal insufficiency, cortisol levels won’t rise in response to ACTH.
  • Insulin tolerance test: A doctor will induce low blood sugar, which should cause your pituitary gland to make ACTH. They’ll measure your cortisol levels periodically. People with secondary adrenal insufficiency won’t have increases in cortisol.
  • CRH stimulation test: You’ll be given CRH, the hormone that stimulates the pituitary gland to make ACTH, and your ACTH levels will be measured periodically:
    • no increase in ACTH indicates secondary adrenal insufficiency
    • a slow increase in ACTH indicates tertiary adrenal insufficiency
  • Imaging: A CT scan can help your doctor see damage to your adrenal glands while an MRI scan can look for potential causes of adrenal insufficiency in the brain.
  • Antibody tests: These test your blood for autoantibodies associated with Addison’s disease.


After taking your medical history, performing a physical exam, and evaluating your sleep log, your doctor can use the following tests to help diagnose narcolepsy:

  • Polysomnogram: A polysomnogram, or sleep study, records different measurements while you’re sleeping. These include:
    • the activity of your brain and muscles
    • your breathing
    • your eye movements
  • Multiple sleep latency test (MSLT): An MSLT helps determine how quickly you fall asleep and how fast you enter REM sleep. You’ll be asked to take several short naps separated by a couple hours. People with narcolepsy tend to both fall asleep and enter REM sleep more quickly.
  • Hypocretin measurement: In some situations, it may be helpful to measure the amount of hypocretin in your cerebrospinal fluid. This is done using a lumbar puncture.


Adrenal insufficiency

The treatment for adrenal insufficiency involves replacement of the hormone cortisol. This can be done through drugs like hydrocortisone, dexamethasone, or prednisone.

Taking a drug called fludrocortisone can help maintain electrolyte balance in people who also don’t make enough aldosterone.


There isn’t a cure for narcolepsy. Instead, symptoms are managed using a combination of medications and lifestyle changes.

Medications for narcolepsy can include:

Lifestyle changes are also important, including setting up a regular sleep schedule, taking shorter naps during the day, and relaxing before bedtime.

If you have any of the following symptoms, it’s a good idea to see a doctor:

  • excessive daytime sleepiness or fatigue, especially if it’s interfering significantly with your daily life
  • frequent disrupted sleep
  • muscle weakness, whether it’s chronic or comes on suddenly

A doctor can evaluate your symptoms and test to see what may be causing them. After a diagnosis is made, they can develop a treatment plan that can help you to manage your condition.

Narcolepsy is a neurological condition affecting sleeping and waking. It causes symptoms like excessive daytime sleepiness, sleep attacks, and sudden instances of muscle weakness.

While some narcolepsy symptoms like excessive tiredness and muscle weakness overlap with adrenal insufficiency, the two conditions have many other differences in symptoms, causes, diagnosis, and treatment.

You may have also heard narcolepsy symptoms be compared to those associated with something called adrenal fatigue. However, adrenal fatigue is not recognized as an actual medical condition at this time.

Regardless, see a doctor if you have excessive tiredness, muscle weakness, or disrupted sleep that significantly interferes with your daily life. It’s possible that your symptoms are due to a medical condition that needs to be treated.