Thyroid nodule 4a is graded under thyroid ultrasound, and patients with thyroid nodule 4a are advised to avoid strenuous exercise. For patients with thyroid nodule 4a, strenuous exercise is not recommended; strenuous exercise may damage the nodule, leading to complications such as bleeding and necrosis of the nodule. Strenuous exercise will also put the body in a state of fatigue, impairing the body’s immune function and making it susceptible to microbial attacks such as bacteria and viruses. For patients with thyroid nodule 4a, moderate exercise can enhance the patient’s immunity and strengthen the cardiopulmonary function. Therefore, patients with thyroid nodule 4a should not exercise strenuously, and should follow the doctor’s advice on the way and amount of exercise, and should go to the hospital in time when discomfort occurs during exercise.