For example, people who have had a stroke may become paralyzed for life. People who are weak from an infection may have no long-term effects after treatment. People with cancer may die if treatment fails. Weakness is not contagious and poses no risk to others. But if the cause of weakness is an infection, the infection may be contagious.
Treatment depends on the cause.
For example, an infection may be treated with antibiotics. An autoimmune disorder may be treated with drugs to suppress the immune system, such as corticosteroids. People with cancer may need surgery, chemotherapy , or radiation therapy . People with a muscle injury may need to apply ice to the muscle, take pain medication and rest. Side effects depend on the treatments used.