Illness-related fatigue: More than just feeling tired

A common refrain during the COVID-19 pandemic is, “I’m so tired.” After months of adjusted living and anxiety, people are understandably weary. Parents who haven’t had a break from their kids are worn out. Those trying to juggle working from home with homeschooling are stretched thin. Between concerns about health, finances, and isolation, everyone is feeling some level of additional stress during this unusual time, and that’s tiring. We all could use a good, long nap — or better yet, a vacation.

But while a break would be nice, most people — except those who are actually sick with COVID-19 or other illnesses — are able to push through their fatigue, precisely because they aren’t sick. “Tired” is a nebulous word that covers a broad spectrum of levels of fatigue. A crucial distinction, however, is between regular fatigue and illness-related fatigue.

Regular fatigue

Everyday fatigue that is not illness-related starts with a baseline of health. You may feel sleepy, you may in fact be sleep-deprived, or your body and mind may be worn out from long hours, exertion, or unrelenting stress — but you don’t feel sick. Your muscles and joints don’t ache like when you have the flu. You are capable of getting out of bed and powering through the day, even if you don’t want to. A cup of coffee or a nap might perk you up.

This type of fatigue is usually related to external factors: lack of sleep, stress, an extra-hard workout. But internally, your body is working well: your glands and organs are operating properly; infection is not depleting your body of energy; your nervous system may be overtaxed, but it’s not frayed from actual impairment.

Illness-related fatigue

When I was acutely ill with persistent Lyme, babesiosis, and ehrlichiosis (all tick-borne illnesses), as well as chronic Epstein-Barr virus, a good night’s sleep did nothing. Naps were staples of my day that helped me survive but didn’t improve my energy. Drinking a cup of coffee was akin to treating an ear infection with candy. No matter how much I rested, my exhaustion persisted.

I felt like I had the flu, except it lasted for years. My whole body ached. I suffered migraine headaches. I had hallucinogenic nightmares. Exercise was out of the question; at times, I was literally too tired to walk up a flight of stairs or sit at the dinner table. I couldn’t concentrate, unable to read or watch TV. Sometimes I was too tired to talk.

There was no pushing through this level of fatigue, because it was caused by internal factors: illnesses that were ravaging my body. Only when they were adequately treated did I start to get my energy back.

For me, the root causes were bacterial infections (Lyme, ehrlichiosis), a parasite (babesiosis), and a virus (Epstein-Barr). Profound fatigue may also result from a host of other diseases and conditions, including chronic fatigue syndrome, fibromyalgia, and multiple sclerosis.

Is it everyday fatigue or illness-related fatigue?

When determining whether your tiredness is everyday fatigue or illness-related, consider the following questions:

  • Do you feel worn out, or do you feel sick?
  • Have you experienced this before, or does it feel more extreme or unrelenting?
  • When you lessen the load of external factors (work, stress, long days) does the fatigue improve, or does it persist?
  • Do you feel refreshed after a good night’s sleep or a nap?
  • Can you go about your day, or is it impossible to get out of bed?
  • Has the fatigue persisted longer than you would expect?
  • Are you experiencing other symptoms that might point to illness?

The bottom line

No one knows your body better than you do. You know what feels normal, and you know what you feel like when you’re sick. If you are not responding to regular fatigue remedies, your fatigue has persisted over time, you have other symptoms, or you just don’t feel right, it’s probably time to call your doctor.

Related Information: Boosting Your Energy


  1. Alex

    This checklist is so helpful!

  2. Patti Klein

    I’ve been reading Jennifer Crystal’s work for years and I’m excited to see her reaching a wider audience. We’re all fatigued during this pandemic but you articulate so well the difference between everyday fatigue and illness-related fatigue. Your discussion about both and your questions at the end go far in allaying our fears about Covid related illness or other underlying causes. Thank you, Jennifer, for a most informative and accessible blog.

  3. Lisa

    I couldn’t agree more with you. I’ve been fighting chronic fatigue and a slew of other symptoms for over 5 years now and I’m just plain tired of hearing doctors say there’s nothing wrong with me, it’s just menopause and to suck it up. About a month about my suspicions came to a head as now my thyroid is visibly enlarged. I was also quite surprised to learn that the tests they did on my thyroid every year aren’t the right test to even see if I have Hypothyroid or even more so, Hashimoto’s! I’m finally getting the right test done, however, funny but the PCP told me they don’t offer these tests to patients cause insurance won’t pay for them. I didn’t care and asked them to run them anyway. Until the test are done, I can’t be for sure to exactly what extend it is, but I should have listened to what my body’s been telling me for years.

    • Beth Staropoli

      Hi Lisa,

      Can you tell me what tests you’re referring to? I have been battling this for years and I feel as though the testing they perform is inadequate at best. I don’t care about the insurance either. It’s worth it to get answers and know what’s going on.
      Thank you,


  4. Puddlelily

    It’s helpful to have descriptions of each type of fatigue. I wonder about the long term effects of living in the heightened state of emergency. Does the day to day stress of operating in a pandemic world wear down one’s immune response? Does depression contribute to a sense of fatigue?

  5. Michelle

    This is a super helpful list of questions to ask yourself if you’re not sure you’re fatigued from illness or from external factors. Also, fatigue is often worn as a badge of honor in our culture: we should stop proudly proclaiming our sleep-deprivation and focus on overall health instead!

  6. Edward O'Malley, PhD

    What Jennifer is saying is not only correct but provides hope-once the underlying issues are treated, or maybe a better term would be managed, some energy returns and some “normal” life activities may be resumed.

    With this kind of unrelenting illness-related fatigue, hope at least offers encouragement to keep looking for solutions, a direction, a way to keep moving forward.

  7. Elise

    I really appreciate your blog post! Well written. This perfectly captures the dilemma I’ve had at times in my life trying to figure out if something is short-term fatigue vs. long-term. I love that you validate people listening to and knowing their own bodies. I got tested after a period of fatigue and my doctor told me everything was fine. But I knew that something wasn’t right. I kept persisting and finally an endocrinologist confirmed my problems with my thyroid. So, I’m glad I listened to my body. My mother, who has had lyme in the past, had a similar challenge. She really had to fight for testing, which eventually confirmed that she did in fact have lyme. Women especially have to often fight to be listened to and believe in the healthcare industry. Thank you for addressing this.

  8. fitnesssculpts

    What you are saying is correct but this not a temporary issue it’s permanent we need to learn to live with this pandemic

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