I thought I would try to answer this question, as best I know how, since, I figure, there are lots of newcomers with these same questions.

Chronic Fatigue Syndrome and Fibromyalgia are not the same thing although they are often diagnosed together. 

 Chronic fatigue syndrome is a condition of prolonged and severe
tiredness or weariness (fatigue) that is not relieved by rest and is
not directly caused by other conditions. (Bear in mind that Fibromyalgia can cause fatigue)

Fibromyalgia is a common condition characterized by long-term,
body-wide pain and tender points in joints, muscles, tendons, and
other soft tissues. Fibromyalgia has also been linked to fatigue ...

Also I noted that Inflammatory Arthritis is also on that list.

Inflammatory arthritis refers to those conditions of the joints that involve the immune system and inflammation.

Myostasis means muscle weakness.

Myalgia means muscle pain.

I have spent a lot of time researching terms because I have been diagnosed with all these things. Today, my current diagnoses is Inflammatory Osteoarthritis. While this sounds like an oxymoron my PA described it to me as all the same symptoms of RA including the pain, severe fatigue & inflammation of the joints without the damage to my joints. The term Inflammatory Arthritis is often substituted for Inflammatory Osteoarthritis. I hope this helps.

 

God bless and keep you,
Bette

Current DX: Inflammatory Ostearthritis (apparently this is not an oxymoron), IBS, Fibro.
Current Meds & what they are for: Plaquinil (arthritis)Triamterene/Hctz (decrease water retention), Dicyclomine (IBS), Ropinirole (Restless Leg), Lexipro (AntiDepressant), Allopurinol (Uric Acid Reducer), Lortab (Pain), Flexiril (Muscle spasms), Savella (Fibromyalgia), Omeprazole DR (decrease stomach acid), Naproxen Sodium (Anti-inflammatory), Omega 3 Fish Oil (anti-inflammatory), Super B-Complex, Concentrated Black Cherry (Uric Acid Reducer).