Thyroid nodules are solid or fluid-filled lumps that form within your thyroid, a small gland located at the base of your neck, just above your breastbone. The great majority of thyroid nodules aren’t serious and don’t cause symptoms. Thyroid cancer accounts for only a small percentage of thyroid nodules.

Symptoms

Most thyroid nodules don’t cause signs or symptoms. Occasionally, however, some nodules become so large that they can:

• Be felt
• Be seen, often as a swelling at the base of your neck
• Press on your windpipe or esophagus, causing shortness of breath or difficulty swallowing

In some cases, thyroid nodules produce additional thyroxine, a hormone secreted by your thyroid gland. The extra thyroxine can cause symptoms of hyperthyroidism such as:

• Unexplained weight loss
• Increased perspiration
• Tremor
• Nervousness
• Rapid or irregular heartbeat

A few thyroid nodules are cancerous (malignant), but determining which nodules are malignant can’t be done by symptoms alone. Most cancerous thyroid nodules are slow growing and may be small when they’re discovered. Aggressive thyroid cancers are rare, but these nodules may be large, firm, fixed and rapid growing.

When to see a doctor

Although most thyroid nodules are noncancerous (benign) and don’t cause problems, ask your doctor to evaluate any unusual swelling in your neck, especially if you have trouble breathing or swallowing. It’s important to evaluate the possibility of cancer.

Also seek medical care if you develop signs and symptoms of hyperthyroidism, such as:

• Sudden weight loss even though your appetite is normal or has increased
• A pounding heart
• Trouble sleeping
• Muscle weakness
• Nervousness or irritability

Causes

• Iodine deficiency.

 

• Overgrowth of normal thyroid tissue.
• Thyroid cyst.
• Chronic inflammation of the thyroid (thyroiditis).
• Multinodular goiter.
• Thyroid cancer.