Myasthenia gravis is a rare autoimmune disorder that causes extreme weakness in the skeletal muscles. It is caused by a malfunction of the body's immune system, which results in antibodies attacking the acetylcholine receptors at the junction between the nerve ending and the muscle. This reduces the ability of the nerve ending to stimulate the muscle, leading to a decrease in muscle strength.
The exact cause of the malfunction in the immune system is unknown, but there are some theories. One is that it may be caused by a viral or bacterial infection that triggers the production of antibodies against the acetylcholine receptors. Another is that it may be caused by a genetic predisposition or a combination of environmental and genetic factors.
It is thought that Myasthenia gravis is more common in women than men, and more common in people of certain ethnic backgrounds, such as those of Mediterranean descent. In addition, the disorder is more likely to occur in people who have a family history of the disorder, or who have other autoimmune diseases, such as lupus or rheumatoid arthritis.
Myasthenia gravis is typically treated with medications that improve the function of the acetylcholine receptors, such as pyridostigmine or neostigmine. In some cases, surgery may be recommended to remove the thymus gland, which is believed to be a source of the antibodies that attack the acetylcholine receptors. In addition, immunosuppressive medications may be prescribed to suppress the immune response.