Myasthenic crisis is the life threatening maximal manifestation of myasthenia gravis. Severe dysphagia and respiratory insufficiency demand admission to an intensive care unit (ICU). At variance, the timely recognition and treatment of myasthenic exacerbation may prevent a manifesting crisis. This reviews deals with red flags that pronounce exacerbation and crisis. Myasthenic crisis is an important differential diagnosis of bulbar symptoms and dysphagia. We elaborate on a structured and comprehensive approach to myasthenic crisis on the ICU. Hallmarks of therapy are symptomatic treatment with acetylcholine esterase inhibitors, plasmapheresis or immunoadsorption, polyvalent immunoglobulins, an early start of steroids and immunosuppressants, namely azathioprine, and a consequent escalation to monoclonal antibody therapy, with rituximab being the first choice. Special demands in ICU treatments are a structured weaning concept, consequent treatment of comorbidities and complications, first and foremost infections, dysphagia management, and comprehensive prevention and treatments of delirium.