Most thyroid nodules do not cause symptoms and are so small that you cannot feel them. They often are found during a physical exam or when another test, such as a CT scan or ultrasound, is done for a different reason.

If your thyroid nodule is big, you may be able to feel it or you may notice that your neck is swollen. In rare cases, you may also:

• Feel pain in your throat or feel like your throat is full.
• Have a hard time swallowing.
• Have a hard time breathing.
• Feel nervous, have a fast heartbeat, sweat a lot, lose weight, or have other symptoms of hyperthyroidism (too much thyroid hormone).
• Feel tired or depressed, have memory problems, be constipated, have dry skin, feel cold, or have other symptoms of hypothyroidism (too little thyroid hormone).

A biopsy is the only way to tell if a thyroid nodule is cancerous. But cancer may be more likely if you have:

• A single, hard lump that feels very different from the rest of the thyroid tissue or other thyroid nodules.
• A nodule that keeps growing for weeks or months.
• A nodule that does not move when you touch it.
• Swollen lymph nodes in your neck.
• A hoarse or scratchy voice that does not go away.

Some other conditions that cause similar symptoms include hyperthyroidism and thyroiditis.