It's not at all unusual for fibromyalgia to be misdiagnosed as another condition and vice versa, as symptoms of fibromyalgia are similar to that of other illnesses and there are no lab tests to definitively identify fibromyalgia. Here are seven conditions commonly mistaken for fibromyalgia.
Chronic Fatigue Syndrome
ME/CFS is the condition that is probably most often confused with FM. That's understandable since an estimated 70% of people who have one also have the other. The symptoms of each are remarkably similar. So much so that some experts believe FM and ME/CFS are slightly different expressions of the same basic illness.
Hypothyroidism is a condition in which the thyroid gland does not produce enough thyroid hormone. This is another condition that shares a lot of FM's symptomatology. Some symptoms common to both include joint or muscle pain, fatigue, sensitivity to cold, constipation, depression and weight gain.
Lupus is an autoimmune disease, meaning the immune system of a person with lupus will attack normal cells as if they were an outside invader. This can cause inflammation, tissue damage and pain throughout body, which feels very much like the widespread body pain of FM.
The two most common types of arthritis are osteoarthritis and rheumatoid arthritis. Osteoarthritis is generally caused by age-related deterioration of the cartilage in joints, which can lead to tissue and bone damage. Rheumatoid arthritis is an autoimmune disease that causes inflammation and destroys the lining of the joints. The main symptom similarities between FM and arthritis are painful joints and morning stiffness.
Multiple Sclerosis is a disease in which the body's immune system eats away at the myelin sheath that covers and protects the nerves. This interferes with the brain's ability to communicate with the rest of the body. Symptoms FM and MS have in common may include pain, fatigue, numbness, tingling, cognitive impairments, poor coordination and blurred vision.
For years people with FM have been told by doctors that they're “just depressed.” Although depression is often listed as a symptom of FM, clinical depression is actually a separate and distinct condition that sometimes overlaps with FM. Some common symptoms that may be shared by FM and depression are pain, fatigue, and difficulty with memory and concentration.
Polymyalgia rheumatica is form of arthritis that causes muscle pain in mulitple parts of the body and rarely occurs in anyone under 50. It shares some of FM's most prominent symptoms – pain, achiness, morning stiffness and fatigue.