What is a common symptom of myasthenia gravis?

Myasthenia gravis is an autoimmune neuromuscular disorder characterized primarily by weakness and fatigue of voluntary muscles. A hallmark symptom of this condition is the experience of extreme weakness that worsens after periods of activity, particularly with repetitive movements. This phenomenon occurs because of the increased demand for acetylcholine at the neuromuscular junction, which is impaired in myasthenia gravis due to antibodies disrupting normal transmission.

Patients may notice that their strength diminishes after exertion and improves after rest. This fluctuation in muscle strength, combined with fatigue, is central to the diagnostic criteria for myasthenia gravis and helps differentiate it from other neuromuscular disorders. The presence of this specific symptom is crucial for clinicians when evaluating a patient suspected of having this condition, making it the most pertinent answer in this context.