Can Rheumatoid Arthritis Affect Muscles?

Rheumatoid arthritis (RA) is a rheumatic disease that involves the abnormality of your immune system. Still, it primarily affects the joint – causing classic symptoms of arthritis such as joint stiffness, swelling and pain. But it’s not only about joint problem since its effect is systemic. In other words it can affect the entire body, including non-joint structures. Can it also affect your muscles?

RA affects your body systematically

This inflammatory disease can be both a debilitating and disfiguring condition. Its effect to the joints can be significant enough to make your daily activities extremely difficult.

Typically, it initially tires your daily tasks. And then eventually, you will not able to do them at all (this is especially true if the disease is poorly controlled).

image_illustration459Some common complications caused by RA that affect your bone and joint include:

  1. Both RA and some of its treatments can increase the risk of bone fractures (osteoporosis).
  2. Over time, the affected joint will lose their range of motion. In worse scenario, they may become deformed.
  3. Carpal tunnel syndrome, a neuropathy (nerve damage) caused by irritation or/and compression of the median nerve in your wrist. Numbness, tingling, and aching in part of the hand (including thumb or finger) are usually the classic symptoms of this syndrome.
  4. Cervical myelopathy, a condition in which your joints dislocate at the top of your spine. It can significantly affect your mobility since it causes extra pressure to your spine.
  5. The inflammation of RA may also cause inflammation in the tendon, causing tendon rupture. For example, people with RA can have tendon rupture on the backs of their fingers.

The good news, new treatments are more effective to control the disease. With prompt treatment, RA is not the end of everything and you can have an average expected lifespan (see more about the prognosis in here).

The bad news, however it’s not always easy to cope with the disease. Although RA mainly affects your joints, again it can affect the entire body.

As written earlier, RA is associated with the abnormality of your body immune system. Therefore, it is also called ‘autoimmune disease’.

Normally, your immune system acts like the body’s defense system against infection and illness. But this mechanism goes awry if you have autoimmune disease. The immune system can mistakenly attack its own healthy tissues or organs, leading to a number of complications.

Abnormal function of immune system in people with RA can also cause problems in non-joint structures of the body. So the effect of the disease can be systemic.

It’s possible for the systemic inflammation of the disease to causes complications that have nothing to do with the joint, such as:

  1. Eye problems. There are a number of eye complications associated with RA. The main ones include inflammation of the white of the eye (scleritis), inflammation of a soft-thin membrane covering the white of the eye called episclera, Sjogren’s syndrome (a disorder that affects the glands that produce tears, making your eye feel gritty and dry).
  2. The systemic RA inflammation can also affect your heart and blood vessels, leading to a number of consequences such as cardiovascular diseases, pericarditis (inflammation of membrane surrounding the heart), atherosclerosis (hardening and narrowing of the arteries), and stroke.
  3. Lung problem. RA can increase the risk of developing inflammation and scarring of your lung’s tissues.
  4. Skin problem.
  5. Increased risk of infections. RA and some of its medications can impair your immune system. As a result, you may get more infections.
  6. Increased risk of lymphoma (cancer that affects lymph system).
  7. Psychological problems. RA can also affect you psychologically. For example, the chronic symptoms of the disease can put you at high risk of depression.

Can rheumatoid arthritis affect your muscles?

Now you know that RA is systemic inflammatory disease that can affect many parts of the body. It can also affect your muscles. For example, sometimes it is associated with muscle problems such as myositis and myocarditis!

Myositis

It is a term that refers to the inflammation of the muscles. It can result from certain medications, infections, or an underlying medical condition with the immune system (such as rheumatoid arthritis and lupus).

There are several types of myositis. The main ones associated with the abnormality of the immune system are polymyositis and dermatomyositis.

Polymyositis

It can affect many different muscles of your body – especially muscles of your hips, thigh, shoulders, neck, and upper arms. The symptom usually develops gradually.

Typically, the muscle weakness affects both sides of the body. For example, if you have it in your left shoulder’s muscles, you tend to also have the same problem in your right shoulder. But it is usually not followed with skin rash.

Polymyositis is quite rare, but it can occur together with RA or another autoimmune disease. It’s incurable, though prompt treatment can help preserve and improve your muscle strength & function. The goal of the treatment is to make the disease go into remission.

Poorly-controlled polymyositis can turn into serious. Over time, it may cause some of the following complications: