Skip to main content


Medically reviewed by Last updated on Aug 31, 2022.

What is polymyositis?

Polymyositis is a condition that causes inflammation and weakness of your muscles. The arms and legs are most often affected. The symptoms usually get slowly worse over weeks to months. The cause may not be known. Your immune system may attack your muscle tissue for unknown reasons. Viruses may also cause polymyositis.

What are the signs and symptoms of polymyositis?

The most common symptom is muscle weakness in the upper arms, thighs, and hip. You may also have weakness in the muscles of your neck, lungs, or heart. You may have trouble with daily activities, such as getting up from a chair, combing your hair, or lifting objects. You may also have any of the following:

  • Joint pain or swelling
  • Shortness of breath
  • Tiredness or weight loss
  • Trouble swallowing

How is polymyositis diagnosed?

  • Blood tests will show if you have muscle damage.
  • A sample of your muscle tissue will be sent to a lab for tests to find the cause of your weakness.
  • An electromyography measures the electrical activity of your muscles at rest and with movement.

How is polymyositis treated?

Medicines may help decrease inflammation or slow an attack on your muscles by your immune system.

Treatment options

The following list of medications are in some way related to or used in the treatment of this condition.

How can I manage my symptoms?

  • Go to physical and occupational therapy. A physical therapist teaches you exercises to help improve movement and strength, and to decrease pain. An occupational therapist teaches you skills to help with your daily activities.
  • Massage and stretch your muscles. Gentle body massage and stretches may help prevent muscle contractures. A contracture is a shortened muscle that makes a joint difficult to move.
  • Eat a variety of healthy foods. Healthy foods include fruits, vegetables, whole-grain breads, low-fat dairy products, beans, lean meats, and fish. Limit how much salt you eat. This will help you prevent weight gain from steroid medicine.

When should I contact my healthcare provider?

  • You have a fever.
  • You have more weakness than usual.
  • You have trouble standing or walking.
  • You have questions or concerns about your condition or care.

When should I seek immediate care or call 911?

  • You have any of the following signs of a heart attack:
    • Squeezing, pressure, or pain in your chest
    • You may also have any of the following:
      • Discomfort or pain in your back, neck, jaw, stomach, or arm
      • Shortness of breath
      • Nausea or vomiting
      • Lightheadedness or a sudden cold sweat
  • You cannot stand or walk.
  • You cannot swallow.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Ā© Copyright IBM Corporation 2022 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes. All illustrations and images included in CareNotesĀ® are the copyrighted property of A.D.A.M., Inc. or IBM Watson Health

Learn more about Polymyositis

Treatment options

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.