What physical symptom is often associated with myasthenia gravis?

Myasthenia gravis is a chronic autoimmune neuromuscular disorder characterized primarily by muscle weakness. The condition occurs when the immune system mistakenly attacks the communication between nerves and muscles, leading to a reduced number of available acetylcholine receptors at the neuromuscular junction. This results in a decrease in muscle activation and consequent fatigue or weakness, particularly after periods of activity. Patients may experience this muscle weakness in various muscle groups, including those controlling eye movement, facial expression, and limbs. The hallmark of myasthenia gravis is that the weakness tends to worsen with activity and improve with rest, which is a key distinguishing feature of the disorder.