What is myasthenia gravis from which Duterte says he’s suffering?

The disease myasthenia gravis has hit the news after President Rodrigo Duterte revealed that he had been diagnosed with the disorder. 

According to Mariz Umali's report on "24 Oras",  the United States National Institute of Neurological Disorders and Stroke said  myasthenia gravis is a chronic autoimmune neuromuscular disease that causes muscle weakness.

In particular, the disease affects the muscles that are involved in movement and breathing.

Among the symptoms of the disease are droopy eyelids, blurred vision, changes in facial expression, and difficulty in swallowing, breathing, and speaking.

People suffering from myasthenia gravis may also feel weakness in their necks, arms, hands, fingers, and legs.

The disease can affect anyone regardless of age, but it is more commonly found among men aged 60 years and older and women aged 40 years and younger. —Julia Mari Ornedo/NB, GMA News