Hi, and welcome. You must be terribly worried about your son. This is a great place to ask questions.

Myasthenia gravis is an autoimmune disease. That means that your immune system, which is supposed to protect you from germs, starts attacking some part of your body by mistake. No one knows why. In myasthenia gravis, the immune system attacks certain cells in the muscles so that they can't communicate well with the nerves that tell them when to move. That makes the muscles get tired easily, and become weak.

We don't think about eyelids as needing a lot of muscle strength, but keeping your eyes open requires constant use of the muscles around your eyes. That's why people with myasthenia often have droopy eyelids (ptosis). With myasthenia, your muscles usually get stronger when you rest, and get tired quickly when you use them. Most people with myasthenia are stronger in the morning and weaker in the evening. Are your son's eyes droopier as the day goes on?

I'm glad that your son's doctor is testing his blood. They're looking for the antibodies that might be attacking his muscles. If they find them, they will know for sure that he has myasthenia, and then they can start treating him. There are medicines that work well. A lot of times they also remove a gland in the chest called the thymus. This works very well in a lot of children--sometimes it cures them for good.

I hope this helps. Please feel free to ask any questions, and let us know what the tests say.

Abby