Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction, due to the binding of autoantibodies to the nicotinic acetylcholine receptor (AChR), or more rarely to a muscle specific kinase (MuSK). It affects most of the time young women and old patients, with a tendency toward increasing incidence and prevalence. Clinical presentation, with fluctuating weakness of ocular, facial and bulbar muscles has a wide range of severity. Evolution is characterized by remissions and exacerbations. The goal of treatment is a complete remission, which implies a sustained collaboration between the general practitioner and the specialized centre and the use of symptomatic treatment (anticholinesterasic) in association with immunomodulators/suppressors (prednisone and azathioprine); although other treatments are available.