Myasthenia gravis is a condition in which the communication between muscles and the nerves that control them break down, says Mayo Clinic. The people most likely to contract myasthenia gravis are women under age 40 and men over 60.
The symptoms of myasthenia gravis include weakness in the muscles of the legs and especially the arms, drooping eyelids, double vision and difficulty controlling the muscles involved with eating, speaking and breathing, posits Mayo Clinic. Though the disease can attack any muscle in the body, these muscle groups are the ones most often affected.
The symptoms of myasthenia gravis are exacerbated the more the muscle is used, and resting the muscle usually brings about an improvement in symptoms, says Mayo Clinic. However, myasthenia gravis has no cure as of 2015, and the symptoms tend to worsen over time.
Myasthenia gravis is an autoimmune disorder, which means that the body is under attack by the antibodies of its own immune system, according to WebMD. Myasthenia gravis results when the nerve cells do not have the right number of receptors for a neurotransmitter called acetylcholine. Acetylcholine tells muscles to contract. Some medical professionals believe that the destruction of acetycholine receptors in myasthenia gravis is related to the thymus gland, which makes some antibodies.