Morning lightness and evening heaviness is a common symptom manifested by patients with myasthenia gravis, an autoimmune disease of the neuromuscular junction. Patients often present with pathological easy fatigue of skeletal muscles throughout the body, and can have involvement of all of the extraocular muscles, skeletal muscles throughout the body, respiratory muscles, and pharyngeal muscles of swallowing, etc. Patients will have morning lightness and evening heaviness. This is because the patient’s skeletal muscles are pathologically susceptible to fatigue. After a night of sleep and rest, the symptoms can be reduced. Therefore, the patient’s symptoms are the lightest each time the examination is done in the morning. After a state of activity, work or exertion during the day, the patient’s symptoms worsen in the afternoon and evening, requiring rest again to relieve them. The use of medications can improve this symptom, and bromipyridamole is usually commonly used.