Fibromyalgia vs PMR: How They’re Different, How They Overlap, and Why It Matters

Polymyalgia rheumatica (PMR) is an inflammatory condition of adults 50+ that targets the shoulders and hips and causes morning stiffness ≥45 minutes. Inflammation blood tests (ESR/CRP) are often high, and most people improve quickly with the right steroid dose and a careful taper.

Fibromyalgia (FM) is a chronic widespread pain condition that can happen at any age, often with fatigue, unrefreshing sleep, and brain fog. Labs are typically normal (it’s not a joint-tissue inflammation disease). Treatment focuses on exercise, education, sleep, and selected medicines — not steroids.

Why these two get confused

People with either condition often describe “aching everywhere,” morning tightness, and trouble lifting arms or getting out of a chair. But the pattern and the tests point in different directions — and treatment choices are very different. Getting the label right prevents months of frustration.

At-a-glance comparison

PMR in plain language

PMR is an immune-driven inflammation problem that targets the shoulder and hip girdles. Doctors listen for the classic story—both-sided shoulder pain/stiffness (often hips), morning stiffness ≥45 minutes, age ≥50—check ESR/CRP, and sometimes use ultrasound to look for bilateral subacromial-subdeltoid bursitis or biceps tenosynovitis.

Most people feel noticeably better in days to a couple of weeks once the dose of prednisone is right, then taper slowly for months.

Fibromyalgia in plain language

Fibromyalgia is a chronic pain processing condition — the nervous system becomes extra sensitive to pain signals. People often have widespread pain, fatigue, poor sleep, and thinking/attention problems (“fibro fog”). There isn’t joint-lining inflammation the way there is in PMR, so routine blood tests are usually normal.

Diagnosis uses 2016 ACR criteria, which score Widespread Pain Index (WPI) and Symptom Severity (SS) — no tender-point exam required. First-line care is exercise + education, with targeted medications for some. Steroids and strong opioids aren’t recommended.

How doctors tell them apart (step by step)

1. Where is the pain?
   • PMR: Shoulders (± neck/upper arms) and hips/thighs, both sides.
   • FM: Widespread — above/below waist and on both sides; often includes back, chest wall, jaw, hands/feet, and headache.
2. How long is the morning stiffness?
   • PMR: Typically ≥45 minutes and eases with movement.
   • FM: Morning stiffness can happen but doesn’t come with lab inflammation.
3. What do the labs show?
   • PMR: ESR/CRP usually elevated (rarely both normal).
   • FM: ESR/CRP normal (used to exclude other causes).
4. What does imaging add?
   • PMR: ultrasound often shows bilateral shoulder bursitis/tenosynovitis, which supports PMR.
   • FM: imaging generally normal or nonspecific.
5. How do they respond to treatment?
   • PMR: usually rapid relief with an appropriate prednisone dose.
   • FM: steroids don’t help; best evidence supports exercise, self-management, and selected meds (e.g., duloxetine, milnacipran, pregabalin).

Can someone have both?

Yes. A person over 50 can have true PMR and co-existing fibromyalgia (or develop FM-like symptoms over time). In those cases, steroids may fix the inflammatory part (PMR) while widespread pain, poor sleep, and fatigue remain due to FM—so the plan needs both a safe PMR taper and an FM program (exercise, sleep, mood, pacing).

What to do if you’re not improving on steroids

• If ESR/CRP normalize and shoulder/hip stiffness improves but you still have widespread pain, fatigue, and unrefreshing sleep, ask about fibromyalgia.
• If you had little or no relief from an adequate PMR dose, your team will re-check the diagnosis, consider mimics (e.g., elderly-onset rheumatoid arthritis, rotator-cuff disease), and may evaluate for FM.

Treatment differences that matter

PMR treatment (the inflammation piece)

• Prednisone at a low-to-moderate starting dose, then slow taper guided by symptoms and ESR/CRP; methotrexate for relapse-prone or steroid-sensitive patients.

Fibromyalgia treatment (the pain-processing piece)

• First-line: exercise + education (walking, pool therapy, tai chi/yoga; start low, go slow).
• Medications (for selected people): duloxetine, milnacipran, or pregabalin can help some.
• Not recommended: steroids or strong opioids (lack of benefit + risks).

A simple self-check (not a diagnosis)

• Are you 50+ with new both-shoulder (± hip) stiffness ≥45 minutes and trouble with coat sleeves or getting out of a chair? → Ask about PMR and ESR/CRP.
• Do you have widespread pain, severe fatigue, poor sleep, and brain fog, with normal labs? Ask if you meet 2016 ACR fibromyalgia criteria and discuss an exercise-first plan.

FAQs

Do tender points still matter?
Not for diagnosis. Since 2010/2016, doctors use WPI + Symptom Severity rather than the old 18 tender points.

Can NSAIDs or steroids “cure” fibromyalgia?
No. Evidence and guidelines do not support steroids or NSAIDs as effective FM treatments; care centers on movement, education, sleep, stress skills, and selected meds.

Is PMR lifelong?
Usually no; many people complete treatment over 1–2 years with a safe taper, though some need longer (or low-dose maintenance).

What if my ESR/CRP are normal but my story sounds like PMR?
True PMR with both ESR and CRP normal is uncommon—not impossible—so clinicians look very carefully for mimics (including fibromyalgia).

What to do next

1. See your clinician with a short note of where it hurts, stiffness minutes, and what you can’t do (e.g., overhead tasks).
2. Ask directly: “Do my symptoms fit PMR or fibromyalgia better—or both?”
3. If it’s PMR: discuss a taper plan, relapse signs, bone protection, and GCA red flags.
4. If it’s fibromyalgia: start an exercise-first plan, build sleep skills, and review whether duloxetine, milnacipran, or pregabalin fit you.