What is Myopathy

Myopathy is a condition that causes muscles to be weak and dysfunctional. There are many different kinds of myopathies. Myopathies may be passed from parent to child (inherited), or they may be caused by external factors (acquired).

Inherited myopathies may cause symptoms at birth or in early life. Acquired myopathies may start suddenly at any age. There is no cure for most myopathies.

What are the causes?

Causes of myopathy include:

• Endocrine disorders, such as thyroid disease.
• Metabolic disorders, which are usually inherited.
• Infection or inflammation of the muscles. This is often triggered by viruses or because the body’s defense system (immune system) is attacking the muscles.
• Certain medicines, such as lipid-lowering medicines.

In some cases, the cause is not known.

What increases the risk?

This condition is more likely to develop in:

• People who have a family history of myopathy.
• Women.

What are the signs or symptoms?

Symptoms of myopathy can range from mild to severe. The most common symptoms include muscle weakness, cramps, stiffness, and spasms. These symptoms are usually felt close to the center of the body (proximal). Depending upon the type of myopathy, one muscle group may be more affected than others. In inherited myopathies, symptoms vary among family members.

Other symptoms of myopathy include:

• Muscle pain or tenderness.
• Muscle weakness that gets progressively worse.
• Fatigue.
• Heart problems.
• Trouble breathing.
• Trouble swallowing.

How is this diagnosed?

This condition is diagnosed based on your medical history and tests, which may include:

• Blood tests.
• Removal of a small piece of muscle tissue to be tested (biopsy).
• Electromyogram (EMG).
• MRI.
• Electrocardiogram (ECG).
• Genetic testing.

How is this treated?

Treatment varies depending on the type of myopathy. Treatment may include over-the-counter or prescription medicines, such as disease-modifying antirheumatic drugs (DMARDs) or drugs that suppress the immune system. You may need physical therapy, a brace to stabilize your muscles, or surgery.

Follow these instructions at home:

If you have a brace:

• Wear the brace as told by your health care provider. Remove it only as told by your health care provider.
• Loosen the brace if any part of your body tingles, becomes numb, or turns cold and blue.
• Do not let your brace get wet if it is not waterproof. If it is not waterproof, cover it with a watertight plastic bag when you take a bath or a shower.
• Keep the brace clean.
• Ask your health care provider when it is safe to drive if you are wearing a brace.

General instructions

• Take over-the-counter and prescription medicines only as told by your health care provider.
• Maintain a healthy weight. Follow instructions from your health care provider about eating, drinking, and physical activity.
• If physical therapy is prescribed, do exercises as told by your health care provider or physical therapist.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if:

• You have trouble managing your symptoms at home.
• You have a fever.

Get help right away if:

• You develop breathing problems.
• You develop chest pain.