Is it Fibromyalgia or Chronic Fatigue Syndrome?
What's the Difference?
Some doctors treat fibromyalgia (FMS) or chronic fatigue syndrome (CFS or ME/CFS) separately, while others think they are actually the same thing - or at least, variations of the same condition. According to the Arthritis Foundation, research shows that 50 to 70 percent of people with one diagnosis also fit the criteria for the other.
Similarities Between Fibromyalgia & Chronic Fatigue Syndrome
FMS and CFS are known to have a host of symptoms in common. They include:
- Pain
- Fatigue
- Sleep disorders
- Irritable bowel syndrome symptoms
- Chronic headaches
- Association with Temporomandibular Joint Syndrome (TMJ)
- Cognitive or memory impairment
- Dizziness
- Impaired coordination
Differences Between Fibromyalgia & Chronic Fatigue Syndrome
One key difference, when it comes to a diagnosis, is which symptom is worst - pain or fatigue. The diagnosis could also be influenced by whether your doctor is more familiar with the American College of Rheumatology's criteria for FMS or the CDC's guidelines for ME/CFS.
However, experts have found some significant differences. ME/CFS tends to begin after flu-like symptoms and may be linked to a virus. ME/CFS patients often have high levels of a cellular antiviral enzyme called RNase L, while the level is normal in FMS patients. Also, ME/CFS diagnostic criteria include low-grade fever and sore throat, while FMS criteria do not. Meanwhile, the onset of FMS frequently is traced to a physical or emotional trauma. The pain of FMS gets better with heat and massage, while the pain of ME/CFS does not. Further, people with FMS have tender points and abnormal levels of a cellular chemical called substance P (which transmits pain signals), and this level appears to be normal in those with ME/CFS.
Myalgic Encephalomyelitis / Encephalopathy (ME)
Definition: Alternate names for chronic fatigue syndrome (CFS).
Several countries currently call the condition myalgic encephalomyelitis, ME/CFS or CFS/ME. Some experts use the terms interchangeably, while others consider one a subgroup of the other.
In the United States, advocates are working to have the name of CFS officially changed to ME/CFS due to the widespread belief that the name CFS trivializes the condition and leads to misperceptions of it. Disagreement over whether encephalomyelitis or encephalopathy is more accurate led to the decision to push for the simple acronym ME.
Myalgic means muscle pain or tenderness. Encephalomyelitis means inflammation of the brain and spinal cord. Encephalopathy means altered brain function and structure caused by diffuse brain disease.
Pronunciation: Myalgic: my-AL-jik
Encephalomyelitis: en-SEF-uh-lo-MY-uh-LY-tis
Encephalopathy: en-CEF-uh-LOP-uh-thee Also Known As: CFIDS (chronic fatigue and immune dysfunction syndrome)
Chronic Fatigue Syndrome
Exhaustion, Pain, Flu-Like Symptoms
Chronic fatigue syndrome (CFS or ME/CFS) is much more than just being tired a lot. People with ME/CFS are so run down that it interferes with their lives and can make it hard to function at all. The severity varies, but typically people with ME/CFS say they have trouble staying on top of their responsibilities at home and on the job. Others are severely disabled and even bedridden. Furthermore, they're not just dealing with extreme fatigue but with a wide range of other symptoms, including flu-like symptoms and chronic pain.
After years of research, experts now suspect that something called central sensitization is at least partially to blame for chronic fatigue syndrome. They also believe that's what makes it so similar to fibromyalgia, which shares many of the same features.
The CDC says the first credible evidence of a biological basis for ME/CFS came in 2006, when twenty researchers from different specialties each linked the illness with genes involved in the sympathetic nervous system and what's called the HPA axis. These genes control how your body responds to things like injuries and stress.
Many researchers believe at least some cases of ME/CFS are caused by an abnormal reaction to common infectious agents. The condition is tentatively linked the the Epstein-Barr virus, enteroviruses, human herpesvirus 6 (HHV-6) and Lyme disease, although studies have fallen short of proving a consistent causal link. However, multiple studies suggest that the immune system may be chronically active in people with ME/CFS, which could at least partially explain the fatigue and lack of energy -- basically, your body thinks it's fighting an infection, whether it is or not, and that takes a lot of energy.
Evidence for immune-system activation includes:
- High levels of pro-inflammatory cytokines (a cellular messenger in the immune system)
- Decreased function of natural killer (NK) cells
- Presence of autoantibodies (antibodies that attack your own tissues)
- Reduced response of T cells to specific infectious agents (T cells are white blood cells that attacks infected, foreign or cancerous cells)
Literature on ME/CFS (by different names) dates back to the 1700s. Through the centuries, it's been falsely attributed to various causes and is only now beginning to be better understood by medical sceience. ME/CFS still goes by many names, including "chronic fatigue and immune dysfunction syndrome" (CFIDS), and "myalgic encephalopathy" or "myalgic encephalomyelitis" (ME). Currently, a name change advisory board is working to have the condition officially known as ME/CFS. The call for a name change is rooted in the belief held by some patients and medical workers that the name chronic fatigue syndrome itself trivializes the condition and contributes to continued misunderstanding of it.
Chronic Fatigue Syndrome Symptoms
Symptoms of ME/CFS and their intensity vary from person to person.
Common symptoms include:
- Sudden severe fatigue, especially following a flu-like illness
- Sleep that isn't refreshing
- Muscle and joint aches without swelling
- Intense or changing patterns of headaches
- Sore throat
- Swollen lymph glands in the neck or armpits
- Memory problems/inability to concentrate
- Symptoms have a distict onset
Other symptoms can include:
- Intolerance to alcohol
- Irritable bowel syndrome
- Dry eyes and mouth
- Impaired circulation in the hands and feet
- Visual disturbances
- Painful menstrual periods
For fatigue to be considered severe, it must meet the four following criteria:
- It's not relieved by sleep or rest
- It's not the result of strenuous physical labor
- It significantly lowers your ability to function normally in most situations
- It gets a lot worse after mental or physical exertion, or after you've been sick
Diagnosing Chronic Fatigue Syndrome
After your doctor has eliminated the possiblity that your fatigue and pain are caused by another ailment, it's time to see whether your symptoms fit the criteria for ME/CFS.
According to the most recent guidelines set by the CDC, for a diagnosis of ME/CFS, the patient must have had fatigue for more than six months that impairs normal activities and cannot be attributed to any identifiable medical or psychological problems.
Researchers haven't yet discovered the underlying cause of ME/CFS, and so far the condition is incurable. Only a small percentage of the people who see a doctor for fatigue can be diagnosed with ME/CFS. When a doctor can't find a cause for fatigue but the patient's symptoms don't meet the criteria for ME/CFS, a likely diagnosis is idiopathic (of unknown cause) chronic fatigue.
Fibromyalgia
Fibromyalgia syndrome (FMS) is a chronic condition that causes intense pain in various places around the body, including muscles, connective tissues and joints, as well as a host of other symptoms. It affects more than 6 million people in the U.S.
Doctors classify fibromyalgia as a syndrome, which means it has a group of signs, symptoms and characteristics that occur together. Experts are investigating a new blood test that may be able to detect FMS in up to 50% of sufferers. While this may be available to some patients, others still will have no definitive medical evidence that they're sick. To make a diagnosis, doctors must usually rely on signs and symptoms alone. Complicating the matter, symptoms vary widely from person to person and often, as do their intensity.
Symptoms of Fibromyalgia
People with FMS frequently hurt all over and feel exhausted all the time. Those symptoms often force you to seriously limit your physical activity. It's also common to have problems concentrating and remembering things. A lot of people with FMS have symptoms so severe that they have to quit or modify their jobs.
Because FMS is frequently misunderstood, family, friends, co-workers and even medical providers may not believe the person is actually sick. A proper diagnosis often takes months.
Adding to these considerable frustrations, it can be difficult or impossible to qualify for Social Security Disability benefits. That's in large part because it used to be commonplace for doctors to mislabel any chronic pain of unknown origin as FMS, and the diagnosis is still misused somewhat today.
Keep in mind that the signs and symptoms vary widely from one person to another. Some people have only a few, while others have many. The intensity of symptoms is different in everyone as well, ranging from mildly annoying to highly debilitating.
Common symptoms of fibromyalgia:
- Widespread pain
- Chest pain
- Morning stiffness
- Fatigue
- Sleep disorders
- Anxiety
- Cognitive or memory impairment ("Fibrofog")
- Depression
- Abdominal complaints
Frequently, people with undiagnosed fibromyalgia don't realize that a host of secondary symptoms are related to the pain, fatigue and other primary symptoms. Keeping a detailed list of symptoms can help your doctor make a diagnosis.
Additional fibromyalgia symptoms include:
- Painful menstrual cramps
- Vision problems
- Nausea and dizziness
- Weight gain
- Chronic headaches
- Skin problems
- Muscle twitches and weakness
These lists include the most common symptoms. For a complete symptoms list, click here.
Fibromyalgia & Overlapping Conditions
As if all this weren't enough, several other conditions frequently go along with FMS. Researchers aren't sure whether one condition leads to another or whether they have related underlying causes. Becoming familiar with the symptoms of these disorders can help you determine whether you have more than one.
Overlapping conditions include:
- Chronic fatigue syndrome
- Irritable bowel syndrome
- Temporomandibular joint syndrome (TMJ)
- Multiple chemical sensitivity
- Myofascial pain syndrome
- Restless leg syndrome
History of Fibromyalgia
Doctors coined the term fibromyalgia (fibro - meaning fibrous tissue, my - meaning muscle, and algia - meaning pain) in 1976, but it wasn't until 1990 that the American College of Rheumatology developed diagnostic criteria. While muscle pain is the primary symptom, research found nothing to be wrong with the muscles. For a time, researchers thought it could be an autoimmune disease, such as lupus or rheumatoid arthritis. Now it's widely believed in the medical community that a malfunction of the central nervous system causes FMS, leading to new research into treatments and new hope that fibromyalgia will be not only more treatable, but perhaps even curable. To date, two drugs, Lyrica (pregabalin) and Cymbalta (duloxetine), are FDA approved for treating FMS, but other drug trials are in the works.
Common Fibromyalgia Terms
- Tender points: places on the body that are painful when slight pressure is applied. These are not the same as the trigger points associated with myofascial pain syndrome (MPS). However, people with FMS frequently have MPS as well.
- Flare-ups: times when symptoms are more intense. Many FMS sufferers experience periodic flare-ups separated by remissions, when symptoms recede. Sometimes, flare-ups link up with a woman's menstrual cycle.
