Polymyositis is a condition that causes inflammation and weakness in many different muscles of the body.
What is going on in the body?
This condition is thought to be an autoimmune disorder. An autoimmune disorder is one in which a person's immune system attacks his or her own body.
When a person has polymyositis, the immune system attacks the muscles. This causes muscular inflammation and weakness. Other organs in the body can also be affected by this condition.
What are the causes and risks of the condition?
The exact cause of this condition is unknown. It occurs most often among women between 40 to 60 years old. However, men and children can also be affected.
A person has a higher than normal risk of developing polymyositis if he or she has another autoimmune disorder, such as:
systemic lupus erythematosus. This disorder causes problems with many body organs, including joints, lungs, kidneys, skin, and heart.
systemic sclerosis, or scleroderma, which causes skin hardening and tightness
Sometimes, cancer can cause polymyositis for unknown reasons.