Fibromyalgia is a Functional Pain Syndrome

Until recently, I hadn't heard of the term FPS, which stands for Functional Pain Syndrome. So I looked it up, and here's what I found:

When someone is in pain but doctors can’t find a clear physical cause, it’s often called functional pain. The diagnosis depends on where the pain is felt — for example, in the stomach for people with Irritable Bowel Syndrome (IBS) or in the muscles and joints for those with Fibromyalgia (FM).

Experts are now changing how they think about FPS. Instead of seeing each chronic pain condition as separate, they’re starting to group them under a broader idea called Central Sensitivity Syndrome (CSS). This means that the brain and nervous system are more sensitive to pain signals.

Fibromyalgia is one type of FPS.

Fibromyalgia is a type of Functional Pain Syndrome, which means it causes real pain even though doctors can't find a clear injury or damage in the body.

In my opinion, it would be very helpful if doctors could tell us something about a brand-new pain we are experiencing - is it caused by Fibromyalgia or by something else? Is it just fibromyalgia that just feels different or is showing up in a new area? Is it relted to something completely different and not fibromyalgia? But fibro does not seem to work like that. It is not clear cut and cannot be seen in any blood tests or xrays etc. 

People with fibromyalgia often feel pain from things that wouldn’t bother most people — like a light touch. This is likely because their nervous system has become overly sensitive, a process known as central sensitization.

What is perceived as touch in an individual from the general population is perceived as pain in individuals suffering from FM. This is probably due to their central sensitization.  

Dr David Crabtree & Dr Praveen Ganty 

Central sensitization means the brain and spinal cord react too strongly to pain signals. This happens because of a complicated mix of chemicals in the body that either increase or decrease pain. This might also explain why people with fibromyalgia often feel tired, have memory issues, and struggle with sleep and mood problems.

How does knowing all this help me (I can here you asking)

Knowing that fibromyalgia is a Functional Pain Syndrome can be really comforting and helpful, especially when you're trying to make sense of what’s going on with your body.

It means:

💡 Your pain is real.
Even if tests come back normal, what you’re feeling isn’t "in your head." Your nervous system is just working differently and that’s something good doctors now understand better.

🧭 You’re not alone.
There are many others living with the same condition. It has a name, it has patterns, and there are communities and support out there.

🌱 There are ways to feel better.
Once doctors know what’s really going on, they can focus on treatments that actually help like managing stress, improving sleep, gentle movement, and sometimes medications that calm the nervous system.

❤️ It’s not your fault.
You didn’t cause this. Your brain and body are reacting in a certain way, and now that there’s a clearer understanding of why, you can be kinder to yourself and more hopeful moving forward.

These sources go into more depth if you want to explore the science or treatment options further: 

1. Mayo Clinic Proceedings – “Fibromyalgia: Understanding the Pathogenesis”
   https://www.mayoclinicproceedings.org/article/S0025-6196(15)00243-8/fulltext

2. ScienceDirect – “Neurobiology of central sensitization”
   https://www.sciencedirect.com/science/article/pii/S0306452216302366

3. Verywell Health – “Understanding Central Sensitivity Syndromes”
   https://www.verywellhealth.com/central-sensitivity-syndromes-716160

4. Cleveland Clinic Journal of Medicine (CCJM) – “Fibromyalgia and Central Sensitization Syndrome”
   https://www.ccjm.org/content/90/4/245

5. Common Functional Pain Syndromes                        https://www.bjaed.org/article/S2058-5349(17)30034-3/fulltext

How do doctors tell if it's fibromyalgia or another condition?​

So how do doctors differentiate fibromyalgia from other conditions since fibromyalgia shares symptoms with many other conditions like chronic fatigue syndrome, rheumatoid arthritis, and lupus. 

Here's how doctors usually differentiate fibromyalgia from other diagnoses:​

🩺 1. Patient History & Symptoms

Doctors start by listening to your story:

• Widespread pain (on both sides of the body, above and below the waist)

• Fatigue

• Sleep disturbances

• Cognitive issues ("fibro fog")

• Sensitivity to touch (allodynia), light, sound, or temperature

They’ll also ask:

• How long symptoms have lasted (typically 3+ months)

• If symptoms are persistent or come and go

---

✅ 2. American College of Rheumatology (ACR) Criteria

Instead of the old "tender point" test, doctors now often use these criteria:

• Widespread Pain Index (WPI): Scores how many areas of the body hurt

• Symptom Severity Scale (SSS): Assesses fatigue, cognitive symptoms, and unrefreshing sleep

• A diagnosis is supported if the WPI and SSS scores meet a certain threshold, without another disorder explaining the symptoms.

---

🧪 3. Rule Out Other Conditions

There’s no lab test for fibromyalgia, so doctors order blood work to rule out other possible causes, such as:

• Thyroid disorders

• Vitamin deficiencies (like B12 or D)

• Autoimmune diseases (e.g. lupus, rheumatoid arthritis)

• Anemia

• Infections

---

🤯 4. No Inflammation or Tissue Damage

Fibromyalgia pain doesn’t come from inflammation or joint damage (unlike arthritis or lupus), and imaging usually shows no structural problems. If a patient has pain but normal blood tests and imaging, it supports a fibro diagnosis.

---

🧬 5. Central Sensitization

Doctors consider whether pain may be amplified by the central nervous system. Fibromyalgia is a central sensitivity syndrome, meaning the brain and nerves are overly reactive to sensory input.

---

💡 Bonus: Common Mistaken Diagnoses

Sometimes fibromyalgia is confused with:

• Chronic Fatigue Syndrome (CFS/ME)

• Lyme disease

• Depression or anxiety disorders

• Myofascial pain syndrome

• Multiple sclerosis (MS)

So careful differential diagnosis is key.

I hope this clears up some of the questions you have about why fibromyalgia is diagnosed and not another condition. Of course you can have Fibromyalgia and other diseases as well. 😕 I personally have autoimmune conditions and osteoarthritis as well as Fibro. 

You may also find the following articles interesting:

• How can a doctor diagnose Fibromyalgia which includes why you may find it difficult to get a diagnosis. 
• 14 reasons it may NOT be Fibromyalgia
• 2010 set of criteria for diagnosing Fibromyalgia. 

Treatment options for sleep disorders common in Fibromyalgia

Here is a breakdown of treatments specifically for sleep disorders, especially as it relates to fibromyalgia and a list of reliable sources that support the information.

🛌 General Treatment Options:

1. Sleep Hygiene Practices

• Keep a consistent sleep schedule

• Avoid screens 1-2 hours before bed

• Make the bedroom dark, cool, and quiet

• Use the bed only for sleep and intimacy

• Limit caffeine and alcohol

2. Medications

• Low-dose tricyclic antidepressants (e.g., amitriptyline) – often used to improve deep sleep

• Cyclobenzaprine – a muscle relaxant that can improve sleep

• Pregabalin (Lyrica) / Gabapentin – help with nerve pain and sleep

• Melatonin – natural sleep hormone to help regulate circadian rhythm

• Zolpidem (Ambien) or other sleep aids – sometimes used short-term

3. Supplements

• Magnesium – may help relax muscles and support better sleep

• 5-HTP – can improve serotonin, potentially aiding mood and sleep

• Valerian root – herbal remedy used for sleep

• CBD – anecdotal support for pain relief and relaxation

4. Cognitive Behavioral Therapy for Insomnia (CBT-I)

• One of the most effective long-term treatments for sleep issues

• Helps break cycles of negative sleep habits and anxiety about sleep

5. Treating Co-Existing Conditions

• Sleep apnea: use of CPAP machines

• RLS: iron supplementation or medications like pramipexole

• Managing depression and anxiety, which often impact sleep

6. Gentle Exercise

• Light stretching, yoga, or walking daily can improve sleep quality

• Avoid intense workouts late in the evening

7. Relaxation Techniques

• Guided meditation, breathing exercises, or progressive muscle relaxation before bed

• Apps like Calm or Insight Timer can help

🛌 Specific Treatment Options for Insomnia can be found here

🔬 Scientific & Medical Sources:

1. National Institutes of Health (NIH)

   • Cognitive Behavioral Therapy for Insomnia (CBT-I)
     NIH recognizes CBT-I as a highly effective, evidence-based treatment for chronic insomnia.

2. American College of Rheumatology

   • Recommends low-dose tricyclic antidepressants (e.g., amitriptyline) and muscle relaxants like cyclobenzaprine to help with pain and sleep in fibromyalgia patients.

3. National Sleep Foundation

   • Sleep Hygiene Tips and info on how habits affect insomnia.

4. Mayo Clinic

   • Melatonin and other sleep supplements, info on prescription sleep aids, and managing insomnia in chronic conditions.

5. Journal of Clinical Sleep Medicine (JCSM)

   • Research articles on effectiveness of CBT-I and concerns about long-term use of prescription sleep medications.

6. Arthritis Foundation

   • Articles on fibromyalgia and sleep, emphasizing the need for a combined approach: meds, lifestyle, and therapy.

---

📚 Peer-Reviewed Research Examples:

• Osorio et al. (2015), “The effectiveness of CBT-I in patients with fibromyalgia: A meta-analysis” – Sleep Medicine Reviews

  Found CBT-I improves both sleep and pain levels in fibromyalgia patients.

• Choy, E. (2015) “The role of sleep in pain and fibromyalgia” – Nature Reviews Rheumatology

  Discusses how sleep disruption worsens fibromyalgia symptoms and how restoring sleep improves quality of life.

  
  
  

   

Muscle Relaxant Medications for Fibromyalgia

Managing chronic pain is no easy task, and for many people, muscle relaxants are part of the long-term plan to find relief. But how well do these medications actually work over time—and what are the trade-offs? 

In this study published in Pharmacy and Clinical Pharmacology on September 19, 2024, Dr. Benjamin Oldfield and his team take a deep dive into the long-term use of muscle relaxants for chronic pain. Through a systematic review of existing research, they explore how effective these drugs really are and what side effects patients might face with ongoing use.

Treatments for Fibromyalgia and Similar Conditions

Researchers looked at 11 studies involving 391 people to see how well certain muscle relaxant medications worked for fibromyalgia and related conditions. Out of these studies, 7 were high-quality clinical trials, and 4 were observational studies.

Here’s what they found:

Cyclobenzaprine

• Used in 5 studies, all clinical trials.

• Helped with sleep problems in 3 studies.

• Didn’t show much improvement in other symptoms compared to a placebo (a “sugar pill”).

• One study compared cyclobenzaprine to amitriptyline (another medication), and both worked equally well after 6 months.

• Side effects happened in 0% to 98% of people and included feeling sleepy, dry mouth, and numbness under the tongue for those using a version that dissolves under the tongue.

Tizanidine

• Used in 3 studies, all observational.

• Helped reduce pain while people were taking it.

• When people stopped taking it, their pain got worse again.

• Side effects (in up to 66% of people) included sleepiness, headaches, and dizziness.

Other Medications

• Chlormezanone and carisoprodol: These didn’t help with pain more than the placebo in the studies.

• Eperisone: In one study, it helped reduce pain better than another pain medication (celecoxib) after 2, 4, and 6 weeks.

• Chlormezanone caused nausea in nearly half of the participants, while no side effects were reported for carisoprodol or eperisone.

Notes:

• RCT = Randomized Controlled Trial (high-quality study)

• Cohort Study = Observational study (lower-quality evidence than RCTs)

SEE THE FULL STUDY IN THE JAMA NETWORK AMERICAN MEDICAL ASSOCIATION PUBLICATION HERE 

Have you tried a muscle relaxant for the chronic pain of Fibromyalgia? If so, I would love to read your experiences in the comments. 

Sleep Disorders Common In Fibromyalgia

Fibromyalgia is often linked to sleep issues like insomnia, restless legs syndrome (RLS), and sleep apnea, causing unrestorative sleep and daytime tiredness. Studies show up to 80% of fibromyalgia patients experience sleep problems. These disturbances can worsen symptoms of Fibro, and have a big impact on our daily life.

Here's a more detailed explanation:

Insomnia:

Insomnia is a common issue for many individuals with fibromyalgia, often struggling to fall or stay asleep, resulting in sleepless nights. This can lead to exhaustion and impact daily life. Studies show up to 70% of those with fibromyalgia suffer from sleep disturbances. Specific treatment options for insomnia can be found here on Fibro Files. 

 

Restless Legs Syndrome (RLS):

Restless Leg Syndrome, marked by the urge to move the legs, often affects those with fibromyalgia, further disrupting their sleep patterns. Managing these conditions together can be challenging but essential for better rest. 

 

Sleep Apnea:

While not directly caused by fibromyalgia, individuals with fibromyalgia may be at higher risk for sleep apnea, a condition where breathing repeatedly stops and starts during sleep.  

 

Non-Restorative Sleep:

Fibromyalgia can lead to sleep that feels shallow and unrefreshing, even if the person sleeps for a reasonable amount of time 

 

Daytime Fatigue:

Poor sleep quality and the symptoms of fibromyalgia itself contribute to significant daytime fatigue.

I have written many other articles about sleep and fibromyalgia that may interest you:

• Treatment options for sleep disorders common in Fibromyalgia

• The sleep connection with fibromyalgia

• My unresolved sleep problems when living with fibromyalgia

• Treatments for insomnia in Fibromyalgia

• Sleep problems may predict later pain problems

• Physical Activity and Sleep in Chronic Fatigue Syndrome and Fibromyalgia Syndrome

• Trial results of new treatment for Fibromyalgia targeting non-restorative sleep