Thyroid nodules are usually asymptomatic if they are benign and small in size; if they are too large, they may produce compression symptoms such as dyspnea and dysphagia; if they are combined with thyroid function abnormalities, they may present with symptoms of hyperthyroidism such as fear of heat and excessive sweating, irritability, etc., or with symptoms of hypothyroidism such as fear of cold and fatigue. Thyroid nodules can be visualized with ultrasound, which is the most important imaging tool for evaluating thyroid nodules. Ultrasound can determine whether the nodule is single or multiple, the size of the nodule, the morphologic features of the nodule, and the blood supply of the nodule. By evaluating the morphological features of the nodule, sometimes in conjunction with its blood supply characteristics, ultrasound can help determine the risk of malignancy in thyroid nodules. Patients with thyroid nodules should be seen by a medical professional.