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Living with Polymyositis

A condition that causes long-lasting muscle inflammation and weakness on both sides of the body, mostly in adults.

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Understanding Polymyositis

Polymyositis is a type of inflammatory myopathy, a muscle disease with long-term muscle inflammation and weakness.

It affects the skeletal muscles used for movement, on both sides of the body. It appears mostly in adults and older adults and is more common in women and Black individuals. It shares features with autoimmune disorders, where the immune system mistakenly attacks healthy tissue. It may be linked to viral infections, connective tissue disorders or an increased cancer risk.

Signs & symptoms

Symptoms vary from person to person. GARD lists these among the most common:

  • Weakness of the upper arms and thighs
  • Muscle aches and joint pain
  • Tiredness (fatigue)
  • Fever and weight loss
  • Shortness of breath with activity
  • Cough

Not everyone has every symptom. GARD's list comes from the Human Phenotype Ontology.

Diagnosis

  1. Talk with your doctor

    Share the symptoms you've noticed, when they started and your family health history. Notes and photos can help.

  2. See a specialist

    Specialists who may be involved include autoimmune and inflammatory disease specialists, brain and nervous system specialists and kidney specialists.

  3. Ask which tests can help

    Your care team will decide which exams and tests can confirm the diagnosis.

  4. Connect with expert centers

    Autoimmune Association, Global Autoimmune Institute and Muscular Dystrophy Association may keep lists of experts for this condition.

Care & treatment

Care team
autoimmune and inflammatory disease specialists (rheumatologists); Brain and nervous system specialists (neurologists); Kidney specialists (nephrologists)
Expert care
Expert lists: Autoimmune Association, Global Autoimmune Institute, Muscular Dystrophy Association
Treatment
GARD doesn't list specific treatments for this condition. Your care team will tailor care to your symptoms.
Research
Clinical trials and observational studies may be options. See the research section below.

General information, not medical advice. Your care team makes the decisions.

Everyday life

Living with a rare condition is easier with support.

  • Connect with Autoimmune Association and other patient organizations
  • Keep notes on symptoms, changes and questions for appointments
  • Ask about patient registries that help research
  • Look into financial aid and travel resources for care visits
Bring these questions to your next doctor visit
Which tests, such as a muscle biopsy, will confirm the diagnosis?
Do I need screening for lung problems or cancer?
What treatments can improve muscle strength?

Quick facts

Symptoms usually startAdult and as an Older Adult

GARD says the exact cause is unknown. It shares many features with autoimmune disorders, and some cases are linked to viral infections, connective tissue disorders or cancer.

NeurologicalKidney

Also known as: neuromyositis; pm; pm - polymyositis

Patient organizations

Source: NIH GARD · PolymyositisGARD ID 7425 · GARD page updated September 2026 · Plain-language summary by Know Rare; editorial review pending. General information, not medical advice.

You are more than your diagnosis

Perspectives from people navigating life with Polymyositis.

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The Surprising Link Between Exercise and Myositis

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May Is Myositis Awareness Month

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How Much Do You Know About Your Myositis?

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Explore research for Polymyositis

Explore actively recruiting Polymyositis studies with HealthSpark.

HealthSpark

Find actively recruiting studies for Polymyositis with HealthSpark. Share your city to explore research near you.

  • Recruiting studies from ClinicalTrials.gov
  • Share your city to look for research near you
  • Eligibility is confirmed by the study team

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Powered by HealthSpark, our AI chat helper · Study information from ClinicalTrials.gov · Eligibility is confirmed by the study team.

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