What’s the Difference Between Chronic Fatigue Syndrome and Fibromyalgia?

Fibromyalgia (FMS) and chronic fatigue syndrome (CFS), also called myalgic encephalomyelitis (ME/CFS), are chronic conditions that have similar symptoms. Both cause extreme tiredness, which could cause ME/CSF to be misdiagnosed as fibromyalgia. However, fibromyalgia usually causes more chronic, widespread pain, while in ME/CFS, the distinguishing symptom is extreme fatigue that doesn't go away, even with rest, severely limiting the ability to do daily tasks.

Exercise or physical activity often makes symptoms worse in both conditions, so healthcare providers look carefully at the type and pattern of symptoms to figure out which one a person might have.

Key Differences

Chronic fatigue syndrome and fibromyalgia have many similarities. But each one has distinguishing features that help tell them apart. The key differences can be summarized as follows:

How to Tell Them Apart

While both chronic fatigue syndrome and fibromyalgia involve pain and fatigue, the defining symptom of each condition is different:

• ME/CFS is defined by extreme exhaustion that doesn't get better with rest. It involves heavy exhaustion that interferes with normal activities and symptoms that get worse after even slight increases in mental or physical activity, such as sitting upright.
• Fibromyalgia is defined by pain and tenderness throughout the body or in multiple areas, as well as increased sensitivity to pain. Fibromyalgia pain is often described as aching, burning, or throbbing. Muscle and joint stiffness are also common.

Some people with ME/CFS experience joint pain and muscle aches, but these symptoms are not required for a diagnosis. Likewise, while fatigue and sleep difficulties are common in fibromyalgia, the condition is primarily defined by widespread, unexplained pain.

Diagnostic Criteria

Both ME/CFS and fibromyalgia have criteria to diagnose each condition.

Chronic Fatigue Syndrome

To be diagnosed with chronic fatigue syndrome, the following three primary symptoms are required to be present:

• A noticeable and substantial decrease in the ability to do things you used to be able to do, because of extreme fatigue which lasts for six months
• An increase in symptoms following even minor physical or mental exertion, with symptoms worsening 12 to 48 hours after activity and lasting for days or weeks
• Unrefreshing sleep, or feeling just as tired upon awakening despite a full night's sleep

Plus one of the following:

• Orthostatic intolerance, in which symptoms like lightheadedness, trouble thinking and concentrating, and increased fatigue with prolonged sitting or standing. This can make activities like standing in line, shopping, and showering intolerable for people with ME/CFS.
• Cognitive impairment such as difficulty following a conversation, paying attention, remembering words, and processing information. This is often referred to as "brain fog." People with ME/CFS may not feel as mentally sharp as they once did, preventing them from going to school or working.

Fibromyalgia

Fibromyalgia is diagnosed using two questionnaires that assess pain and symptom severity: the Widespread Pain Index (WPI) and the Symptom Severity Scale (SSS).

The WPI evaluates pain across 19 body areas, awarding one point for each painful region. These regions include the:

• Jaw (left and right)
• Neck
• Shoulders (left and right)
• Upper and lower arms (left and right)
• Hips (left and right)
• Upper and lower legs (left and right)
• Upper and lower back
• Chest
• Abdomen

The SSS assesses the presence and severity of four symptoms, scoring each from 0 (none) to 3 (severe), with a maximum total score of 12. Those symptoms are:

• Fatigue
• Unrefreshing sleep
• Cognitive difficulties (e.g., trouble concentrating or remembering names)
• Somatic symptoms (e.g., pain, dizziness, nausea, or bowel disorders)

To diagnose fibromyalgia, pain must be present in at least four out of five body regions, with symptoms persisting for at least three months.

Additionally, one of the following score combinations must be met:

• A WPI score of 7 or higher with an SSS score of 5 or higher, or—
• A WPI score of 4 to 6 with an SSS score of 9 or higher

This can be a time-consuming process. Not all healthcare providers are comfortable diagnosing fibromyalgia. That means you may need to push for tests or a referral to a specialist.

Additional Symptoms

People with fibromyalgia and ME/CFS often experience additional symptoms beyond their primary diagnostic features, with many of these symptoms overlapping between the two conditions.

In addition to the hallmark feature of ME/CFS—persistent, unrelenting exhaustion—other potential symptoms include:

• New onset or patterns of headaches
• Joint pain without swollen joints
• Muscle pain and soreness
• Stiffness in the arms, legs, or back that makes certain movements hard, like reaching overhead
• Chills and night sweats
• "Brain fog" or problems with concentrating or thinking clearly
• Heart palpitations, fast heart rate, fainting
• Sore throat, tender lymph nodes in the neck

In addition to the hallmark feature of fibromyalgia—widespread, unexplained pain and tenderness—other potential symptoms include:

• Fatigue
• Trouble sleeping
• Muscle and joint stiffness
• Increased pain sensitivity
• Numbness or tingling in the arms or legs
• "Fibro fog" or problems with concentrating or thinking clearly
• Increased sensitivity to light, odors, sounds, and temperatures
• Digestive issues, such as bloating and constipation
  

Can You Have Both CFS and Fibromyalgia?

You can have both chronic fatigue syndrome and fibromyalgia. In fact, many people do. These conditions are considered “cousins,” of a sort. They belong to the same family of illnesses, which is called central sensitivity syndromes.

The symptoms are extremely similar. So, it can be difficult to tell if you have just one or both of these conditions. Until there’s better diagnostic testing, it may sometimes be impossible to tell if you have both. It may never even be clear which one you have, either, depending on your specific mix of symptoms.

Fortunately, the treatments are similar. So, you may get the right treatments even if you’re not correctly diagnosed.

How They're Treated

There’s no standard treatment for ME/CFS or fibromyalgia. Most people end up with multiple types of treatment. It can take a lot of trial and error to come up with a good treatment regimen.

Treating ME/CFS

So far, the Food and Drug Administration (FDA) hasn’t approved any drugs for treating ME/CFS. However, a wide variety of treatment options are available:

• Antivirals: Medications like Ampligen or Valcyte target viruses that may contribute to ME/CFS.
• Antidepressants: Drugs such as Cymbalta, Prozac, or Zoloft are prescribed to address neurotransmitter imbalances in the brain.
• Antianxiety drugs: Medications like Xanax or Ativan are used to manage anxiety symptoms associated with ME/CFS.
• Painkillers: Options such as Advil, Vicodin, or OxyContin are taken to relieve pain, ranging from mild to severe.
• Sleep medications: Drugs like Klonopin or Ambien are prescribed to improve the duration and quality of sleep.
• Topical pain relievers: Products such as BioFreeze and Tiger Balm are applied for localized pain relief.
• Cognitive behavioral therapy (CBT): A type of talk therapy that aims to change negative thought patterns, though it may not address the physiological issues of ME/CFS.
• Graded exercise therapy (GET): A controlled exercise program that attempts to build exercise tolerance but may worsen symptoms in some cases by triggering post-exertional malaise.
• Complementary therapies: Approaches like acupuncture, hypnotherapy, and biofeedback are used to manage symptoms, though research support is limited.
• Supplements: Products such as CoQ10, magnesium, melatonin, omega-3, turmeric, vitamin B12, and vitamin D are commonly used despite limited evidence supporting their effectiveness.
• Lifestyle changes: Strategies include energy management techniques like pacing to avoid overexertion, mild exercise, improving sleep habits, and following a healthy diet to support overall well-being.

Many treatments for ME/CFS, including therapies like CBT and GET, are considered experimental and have limited evidence supporting their effectiveness.

These approaches often fail to address the known physiological abnormalities of ME/CFS and are based on outdated theories that are not backed by research or patient experiences.

In fact, some studies suggest that only a small percentage of people benefit from them, while others report worsening symptoms.

It is essential to consult a healthcare provider before trying any new treatment to ensure it is safe and appropriate for your specific condition.

Treating Fibromyalgia

The FDA has approved three prescription drugs for fibromyalgia: Cymbalta, Savella, and Lyrica. Many other medications and therapies are used as well, with mixed results in both studies and real-world use:

• Antidepressants: These medications target neurotransmitter imbalances associated with fibromyalgia. FDA-approved options include Cymbalta (duloxetine) and Savella (milnacipran), which can help with both pain and mood.
• Anti-seizure drugs: Medications like Lyrica (pregabalin), FDA-approved for fibromyalgia, and Neurontin (gabapentin) work by regulating pain signals in the brain.
• Painkillers: Options range from OTC medications like Advil (ibuprofen) and Aleve (naproxen) to prescription pain relievers such as Ultram (tramadol) and OxyContin (oxycodone). These can help manage pain but may carry risks, especially opioids.
• Muscle relaxants: Drugs like Flexeril (cyclobenzaprine) and Zanaflex (tizanidine) help alleviate muscle pain and improve sleep quality.
• Sleep medications: To enhance sleep duration and quality, providers may prescribe medications like Klonopin (clonazepam), Lunesta (eszopiclone), or Ambien (zolpidem).
• Topical pain relievers: Products like BioFreeze or Tiger Balm are commonly used to relieve localized pain.
• Therapies: Physical therapy focuses on improving strength and flexibility, while occupational therapy helps manage energy, stress, and pain. Talk therapy, including CBT, may address the emotional toll of chronic illness.
• Complementary and alternative medicine: Popular but less-researched options include acupuncture, massage therapy, tai chi, progressive muscle relaxation, biofeedback, and medical cannabis. These may provide relief for symptoms that persist despite other treatments.
• Supplements: Common supplements used for fibromyalgia include 5-HTP, CoQ10, magnesium, omega-3, turmeric, and vitamin D. While evidence is limited, many find these helpful for managing symptoms.
• Lifestyle changes: Key strategies include regular, mild exercise, pacing activities to avoid overexertion, improving sleep habits, mindfulness meditation, and maintaining a healthy diet. Exercise is one of the most consistently beneficial treatments for fibromyalgia.
  

Summary

Fibromyalgia (FM) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have some similar symptoms, like tiredness and trouble thinking, but they are different conditions. FM mainly causes widespread pain, tender spots on the body, and poor sleep, with tiredness often caused by pain and lack of rest.

ME/CFS is known for extreme tiredness that gets worse after doing physical or mental activities, called post-exertional malaise. It also causes poor sleep, trouble focusing, and flu-like symptoms. Unlike FM, ME/CFS often includes dizziness, trouble standing for long periods, and feeling very weak or drained of energy.