Thyroid Nodule
A lump felt or found within the thyroid gland
Quick Facts
- Type: Endocrine / neck lump symptom
- Common causes: Benign growths, cysts, goiter
- Location: Front of the neck
- Mostly: Noncancerous
Overview
A thyroid nodule is a lump that forms within the thyroid, the butterfly-shaped gland at the front of the neck that produces hormones controlling metabolism. Nodules are very common and become more frequent with age. Many are discovered by chance during a physical exam or on an imaging test done for another reason, while some are large enough to be seen or felt as a swelling in the lower neck.
The great majority of thyroid nodules are benign (noncancerous) and cause no problems. A smaller number are cancerous or overactive, so the goal of evaluation is to sort out which nodules need treatment and which can simply be watched. Most people with a thyroid nodule feel completely well.
Common Causes
Thyroid nodules can arise from several different processes:
- Benign overgrowth: A localized overgrowth of normal thyroid tissue (an adenoma or colloid nodule) is the most common cause.
- Fluid-filled cysts: Thyroid cysts, sometimes from degeneration of an older nodule, can form a smooth lump.
- Goiter: A generally enlarged thyroid may contain one or several nodules (multinodular goiter), often linked to iodine levels.
- Thyroiditis: Inflammation of the gland, such as Hashimoto thyroiditis, can produce nodular swelling.
- Overactive nodules: Some nodules independently produce thyroid hormone and cause an overactive thyroid.
- Thyroid cancer: A minority of nodules are cancerous, which is why evaluation matters.
Associated Symptoms
Most nodules cause no symptoms. When they do, features depend on size and whether the nodule affects hormone levels:
- A visible or palpable lump in the front of the neck
- A sensation of pressure, fullness, or tightness in the throat
- Difficulty swallowing or, rarely, breathing if a large nodule presses on nearby structures
- Hoarseness or voice change
- Signs of an overactive thyroid: weight loss, rapid heartbeat, tremor, heat intolerance, anxiety
- Less often, signs of an underactive thyroid such as fatigue and weight gain when thyroiditis is involved
Diagnosis & Evaluation
Evaluation is designed to assess thyroid function and the chance that a nodule is cancerous:
- Physical exam: Feeling the gland for size, firmness, and number of nodules, and checking for enlarged lymph nodes.
- Blood tests: Thyroid hormone and TSH levels show whether the thyroid is overactive, underactive, or normal.
- Ultrasound: The key imaging test, describing a nodule's size, structure, and features that suggest higher or lower risk.
- Fine-needle aspiration biopsy: A thin needle samples cells from suspicious nodules to check for cancer.
- Radioactive iodine scan: Used when blood tests suggest a nodule may be overproducing hormone.
Treatment & Management
Treatment depends on whether the nodule is benign, overactive, or cancerous:
- Watchful monitoring: Most benign nodules are simply followed with periodic exams and ultrasound.
- Treating overactive nodules: Options include antithyroid medication, radioactive iodine, or surgery to control excess hormone.
- Draining cysts: Fluid-filled nodules can be aspirated, which may relieve pressure.
- Surgery: Removal of part or all of the thyroid is advised for cancerous nodules, suspicious biopsies, or large nodules causing compression.
- Cancer care: Most thyroid cancers are highly treatable, often with surgery and sometimes radioactive iodine.
- Hormone replacement: People who have part or all of the thyroid removed may need daily thyroid hormone tablets to keep levels normal.
The specific plan is tailored to biopsy results, hormone levels, symptoms, and personal preference. For the many people whose nodules are benign and stable, the main task is simply attending periodic ultrasounds and exams so any change can be caught early. Newer, less invasive techniques are also available in some centers for certain benign nodules that cause symptoms, offering alternatives to traditional surgery when appropriate.
Self-Care & Prevention
- Most nodules cannot be prevented, but adequate dietary iodine supports thyroid health
- Keep scheduled follow-up appointments and ultrasounds
- Note any growth of the lump or new swallowing or voice changes
- Mention any history of childhood neck radiation or family thyroid cancer to your doctor
- Take any prescribed thyroid medication consistently
When to See a Doctor
See a doctor if you notice a lump in your neck or your thyroid is found to contain a nodule, so it can be evaluated. Seek prompt or urgent care if a neck lump is:
- Growing quickly or feels hard and fixed in place
- Causing trouble swallowing, persistent hoarseness, or voice change
- Accompanied by enlarged neck lymph nodes
Seek emergency care if a neck mass causes difficulty breathing or noisy breathing. Symptoms such as rapid heartbeat, weight loss, and tremor also warrant prompt evaluation for an overactive thyroid.
Frequently Asked Questions
Are most thyroid nodules cancerous?
No. The large majority of thyroid nodules are benign and never cause problems. Only a small percentage are cancerous, which is why doctors use ultrasound and sometimes a needle biopsy to identify the few that need treatment.
How is a thyroid nodule checked for cancer?
An ultrasound describes the nodule's features, and suspicious ones are sampled with a fine-needle aspiration biopsy. The cells are then examined to determine whether the nodule is benign or needs surgery.
Do thyroid nodules need to be removed?
Most do not. Benign nodules are usually just monitored. Surgery is reserved for nodules that are cancerous, suspicious on biopsy, overactive, or large enough to press on the windpipe or esophagus.
Can a thyroid nodule affect hormone levels?
Some nodules produce extra thyroid hormone and cause an overactive thyroid with symptoms like rapid heartbeat, weight loss, and tremor. Blood tests for TSH and thyroid hormone check for this.
When is a neck lump an emergency?
Seek emergency care if a neck mass causes difficulty breathing or noisy breathing. A lump that grows rapidly, feels hard and fixed, or causes persistent hoarseness should be evaluated promptly.
References
- American Thyroid Association. Thyroid Nodules.
- Mayo Clinic. Thyroid nodules — Symptoms and causes.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Thyroid disease.
- MedlinePlus, U.S. National Library of Medicine. Thyroid nodule.