Thyroid Nodules: Thyroid nodules are lumps or growths that form within the thyroid gland. Most thyroid nodules are benign (non-cancerous), but some can be cancerous. Thyroid nodules may not cause any symptoms, or they may cause symptoms such as swelling in the neck, difficulty swallowing, or hoarseness. Depending on the size and characteristics of the nodule, treatment may involve monitoring, medication, or surgery.