“IC’s Related Conditions” series takes a look at conditions that can go hand-in-hand with IC. Not all patients have all of these conditions, but IC patients are more prone to be diagnosed with these conditions than the general population. (As always, this is not intended as medical advice and is for informational purposes only. Any and all medical questions should be addressed with your doctor.)

Chronic Fatigue Syndrome (also known as myalgic encephalomyelitis) is one of the chronic overlapping pain conditions that some IC patients in the central sensitization subtype can struggle with.  CFS is an all-encompassing fatigue that lasts for at least six months and has no other medical explanation. Understanding its symptoms, risk factors, diagnosis and treatment options is important for IC patients since the conditions can overlap.


Along with extreme fatigue lasting at least six months, CFS may struggle with poor sleep, brain fog (difficulty with memory, focus and concentration) and dizziness that’s worse when sitting or standing up after lying down.(1) Symptoms can vary from person-to-person and even in daily severity in the same person. Less well-known symptoms include: sore throat, headaches, enlarged lymph node in your neck or armpits, extreme exhaustion after physical or mental exercise and unexplained muscle or joint pain.(1)

Risk Factors

CFS most commonly impacts young to middle-aged adults. Women are diagnosed with CFS more often than men.(1) In fact, women are four times more likely to get CFS than men, and the same holds true no matter the age at onset.(2)

Some evidence indicates that CFS can be hereditary. If you have a family member with CFS, you have a greater chance of being diagnosed with it as well. Patients may struggle with the other overlapping pain conditions, including: fibromyalgia, irritable bowel syndrome, temporomandibular disorders (TMD or TMJ), IC, post-concussion syndrome, tension headache, chronic pelvic pain (women), chronic prostatitis (men) and multiple chemical sensitivities.(2)

CFS and fibromyalgia, in particular, are often closely related. Researchers, doctors and patients have paired the two conditions and even used them interchangeably. However, research suggests the two are separate conditions with similar symptoms. And they do often overlap. An estimated 50 to 70% of fibromyalgia patients fit the criteria for CFS. While both fibromyalgia and CFS can cause fatigue and pain, the biggest difference is that in fibromyalgia, pain is usually the overwhelming symptom. In CFS, lack of energy is the overwhelming symptom.(3)


CFS doesn’t have a known cause, but it does have a few theories about where it comes from. Some people develop CFS after having a viral infection, especially Epstein-Barr (or mono).(1) Interestingly enough, the Epstein-Barr virus has also been on the radar of some IC researchers who have found some patients developed IC after having the virus.

Some patients with CFS appear to have a slightly impaired immune system and/or a hormonal imbalance. Physical or emotional trauma is a potential cause. Some patients begin having symptoms after an injury, surgery or significant emotional stress.(1)

Of course, we cannot ignore recent brain studies in chronic overlapping pain patients which have found found that the sympathetic nervous system and amygdala are “wound up” leaving these chronic pain patients in an extended “fight or flight” phase. This is known as a central nervous system “maladaption” rather than a mental illness.(4)


No definitive test exists for CFS. It is usually a diagnosis of elimination based on symptoms. According to the U.S. Centers for Disease Control and Prevention, CFS requires three main symptoms plus at least one additional one for diagnosis. Patients must have been experiencing severe fatigue that interferes with their daily lives for more than six months (but also not be lifelong), have post-exertional malaise (worse symptoms after physical, mental or emotional effort) and un-refreshing sleep. Additionally patients should have either impaired memory or ability to concentrate or feelings of lightheadedness or dizziness when standing or both.(5)

Sleep disorders are one thing doctors usually rule out before diagnosing CFS since sleep apnea, restless legs syndrome and insomnia can all have symptoms similar to CFS. A simple blood test can help rule out medical problems with symptoms similar to CFS  such as anemia, diabetes and an under-active thyroid. And, finally, mental health issues can also have similar symptoms, so patients should be checked for things like depression and anxiety as a reason for their fatigue before being diagnosed with CFS.(6) However, patients with CFS can have some of these overlapping conditions as well, which makes diagnosis all the more challenging.


CFS doesn’t have a cure. Its treatment focuses on improving symptoms. No one medication is approved for treating CFS. However, some medications are often used in treating its symptoms since CFS often coincides with other issues. Antidepressants in low doses can help with depression, improve sleep and relieve pain. If a patient has the CFS symptom of getting dizzy when sitting or standing after lying down, they may benefit from medication that regulates blood pressure or heart rhythms. And if CFS is causing some pain, often over-the-counter pain relievers can help ease the pain. For patients who need something stronger, prescription medication used to treat fibromyalgia, like pregabalin (Lyrica), duloxetine (Cymbalta), amitriptyline or gabapentin (Neurontin), might be helpful.(6) Please note, however, that both Lyrica and Cymbalta can be remarkably difficult to get off of and both can cause a severe “discontinuation” (withdrawal) symptoms.(7)

Aside from oral medications, there are other treatment options for CFS. The first is addressing sleep problems. Figuring out how to get the best sleep possible is vital. Undergoing a sleep study to check for sleep apnea could be a good idea. Otherwise, addressing good sleep hygiene is important. Exercise done right can also be helpful. Strenuous and aggressive exercise will aggravate CFS symptoms, but lower impact exercises can help.

Finally, seeing a counselor can also be helpful in treating CFS. Like any chronic health condition, CFS can lead to feelings of depression, anxiety, hopelessness and shame. And those things all trigger more feelings of tiredness. Working with a trained mental health professional can help patients develop coping skills and improve their overall mental wellbeing.



  1. Mayo Clinic Staff. Chronic Fatigue Syndrome. Mayo Clinic. Sept. 24, 2020.
  2. Cassoobhoy A. What Makes Chronic Fatigue Syndrome More Likely?. WebMD. Nov. 20, 2020.
  3. Thompson D. The Common Thread of Fibromyalgia and Chronic Fatigue Syndrome. Everyday Health. Nov. 22, 2011.
  4. Osborne J. Chronic Overlapping Pain Conditions. IC Optimist. Fall 20 / Winter 21. January 2021.
  5. CDC. Could You Have ME/CFS?.
  6. Mayo Clinic Staff. Chronic Fatigue Syndrome: Diagnosis and Treatment. Mayo Clinic. Sept. 24, 2020.
  7. Bullock C. Discontinuation Syndrome and antidepressants. Harvard Health Blog. April 11, 2019