Early thyroid nodules are usually asymptomatic until they reach a certain size and the patient can feel the protrusion in the lower part of the neck, which is diagnosed by the doctor. Thyroid nodules are not necessarily thyroid cancer, most of which are benign, but benign nodules may change. Regular medical treatment and follow-up examination are necessary. The symptoms are described as follows:

• Local swelling or palpation of a lump:

Cancer-induced nodules feel hard, are easy to adhere to surrounding tissues, have poor mobility, and are prone to symptoms of cervical lymphadenopathy.

• Local compression symptoms:

When the tumors compress the recurrent laryngeal nerve, there will be hoarseness; dysphagia and weight loss when they invade the esophagus; hemoptysis, dyspnea and chest discomfort when they invade or compress the trachea.

• Symptoms of local metastasis:

Enlargement of cervical lymph nodes, especially papillary cancer and medullary cancer, is more prone to metastatic enlargement of cervical lymph nodes.

• Symptoms of distal metastasis:

Headache and vomiting caused by brain metastasis from thyroid cancer; cough, hemoptysis and chest discomfort caused by pulmonary or mediastinal metastasis; pain caused by pathological fracture as a result of bone metastasis, and limb limpness and numbness caused by spinal cord metastasis.