<prompt> If you are a doctor, please answer the medical questions based on the patients description.I was diagnosed with Anti Musk Antibody Myasthenia Gravis in September and twice the last being Saturday I woke with severe pain in the middle of my chest and back. It was hard to breathe because it hurt so much. It did ease off and I now have a dull pain.  <response>: Hello! Welcome and thank you for asking on Chat Doctor! Regarding your concern, I would explain that it is important performing a comprehensive differential diagnosis between different possible causes that may lead to such symptoms: - a lung disorder- musculoskeletal pain- a Tacoma considering your positive antibodies- a heart disorder-esophageal spasms, etc. For this reason, I recommend consulting as soon as possible with your attending physician and performing some tests: - a chest X-ray study and pulmonary function tests- a resting ECG and a cardiac ultrasound-complete blood count, PCR, ESR for inflammation- D dimmer levels for possible pulmonary embolism. A chest X-ray study would help investigate for the presence of Tacoma. Hope you will find this answer helpful! Kind regards, 