Myasthenia gravis (MG) is a neuromuscular disorder that causes weakness in the skeletal muscles, which are the muscles your body uses for movement. It occurs when communication between nerve cells and muscles becomes impaired.
The muscles around the eyes tend to be affected first, causing the eyelids to droop. Patients may experience double vision, weakness in the arms and legs, and difficulties chewing, swallowing, speaking, and breathing. Involuntary muscles, such as the heart muscles, are not affected.
Symptoms
- trouble talking
- problems walking up stairs or lifting objects
- facial paralysis
- difficulty breathing due to muscle weakness
- difficulty swallowing or chewing
- fatigue
- hoarse voice
- drooping of eyelids
- double vision
- Speaking: Speech may become soft or nasal.
- Facial expressions: A different or unusual smile may develop if certain facial muscles are affected.
Limb weakness is the first sign in 10 percent of patients. The arm and leg muscles may weaken, affecting activities such as lifting or walking.
When limb muscles are involved, other muscles also tend to be affected, such as the throat, eyes, or face.