MG affects voluntary muscles in the body. Weakness may come and go, become more prominent as the affected muscle is used repeatedly, and improves with rest.
Signs may be generalised or localised:
Common signs include:
Not all signs occur at the same time or are always present. The signs usually occur slowly but may develop suddenly with generalised weakness and rapid weakening of swallowing and breathing muscles. This is termed myasthenic crisis and needs immediate medical attention.