Goitre: Causes, Types, Symptoms, Diagnosis, and Treatment

~Introduction

The thyroid gland is a small butterfly-shaped gland situated in the lower part of the neck, just below the Adam’s apple. It plays a vital role in regulating the body’s metabolism, growth, and development by producing thyroid hormones—thyroxine (T4) and triiodothyronine (T3). When this gland enlarges abnormally, regardless of the underlying cause, the condition is called a goitre.

A goitre is not a disease in itself but rather a clinical sign of an underlying thyroid disorder. It may be associated with normal thyroid function (euthyroid goitre), overactive thyroid (hyperthyroidism), or underactive thyroid (hypothyroidism). Goitres can range from a small swelling that causes no discomfort to a massive enlargement that obstructs breathing or swallowing.

This article will explore goitre in detail—its history, causes, types, pathophysiology, clinical features, complications, diagnostic methods, treatment options, prevention, and global impact.

~Historical Perspective

Goitre has been recognized since ancient times. Records from China, India, and Egypt mention neck swellings, often linked to iodine deficiency. In the 19th century, it was especially prevalent in mountainous regions, where soil lacked iodine. The introduction of iodized salt in the 20th century significantly reduced endemic goitre in many countries, highlighting the critical link between iodine intake and thyroid health.

~Anatomy and Physiology of the Thyroid Gland

The thyroid gland lies in front of the trachea and consists of two lobes connected by an isthmus. Its main functions are:

Production of T4 and T3 hormones that regulate metabolism.
Regulation of growth, brain development (especially in children), and energy expenditure.
Secretion controlled by the hypothalamus-pituitary-thyroid axis:
- The hypothalamus releases TRH (thyrotropin-releasing hormone).
- TRH stimulates the pituitary gland to release TSH (thyroid-stimulating hormone).
- TSH regulates thyroid hormone synthesis and growth of the gland.

Disruption of this axis, nutritional deficiencies, or autoimmune reactions can lead to goitre.

~Causes of Goitre

Goitre has many causes, which can be grouped into several categories:

1. Iodine Deficiency

The most common cause worldwide.
Iodine is essential for thyroid hormone synthesis.
Low iodine intake causes the gland to enlarge in an attempt to capture more iodine from the bloodstream.

2. Autoimmune Disorders

Graves’ disease: Autoimmune stimulation of the thyroid leading to hyperthyroidism and diffuse goitre.
Hashimoto’s thyroiditis: Autoimmune destruction of thyroid cells causing hypothyroidism with compensatory enlargement.

3. Nodular Thyroid Disease

Single nodule (toxic adenoma) or multiple nodules (multinodular goitre) can cause localized or generalized enlargement.

4. Thyroid Inflammation (Thyroiditis)

Subacute thyroiditis (usually viral), postpartum thyroiditis, or chronic thyroiditis may lead to swelling.

5. Genetic Factors

Some inherited conditions affect thyroid hormone production (dyshormonogenesis), leading to congenital goitre.

6. Thyroid Cancer

Malignant tumors can present as a nodular or diffuse goitre.

7. Other Causes

Excess iodine intake (Jod-Basedow phenomenon).
Medications (e.g., amiodarone, lithium).
Radiation exposure.

~Types of Goitre

Goitres are classified based on structure, function, and cause.

1. Diffuse Goitre

Uniform enlargement of the thyroid gland.
Common in iodine deficiency or Graves’ disease.

2. Nodular Goitre

Enlargement due to nodules within the gland.
Solitary nodular goitre: A single lump.
Multinodular goitre: Multiple nodules causing irregular swelling.

3. Endemic Goitre

Occurs in regions where dietary iodine is insufficient.
Affects a significant portion of the population.

4. Sporadic Goitre

Appears in individuals outside endemic areas.
May be due to genetic, autoimmune, or idiopathic causes.

5. Toxic Goitre

Associated with excessive thyroid hormone production (Graves’ disease, toxic multinodular goitre, toxic adenoma).

6. Non-toxic Goitre

Enlarged thyroid without abnormal hormone production.

~Risk Factors

Female sex (women are more prone due to hormonal influences).
Age over 40.
Family history of thyroid disease.
Living in iodine-deficient areas.
Smoking (thiocyanates interfere with iodine uptake).
High or low iodine intake.
Radiation exposure to the neck.

~Symptoms and Clinical Features

The presentation of goitre varies depending on its size, cause, and thyroid function.

1. Neck Swelling

The most obvious sign.
Can be diffuse or nodular.
May move up and down when swallowing.

2. Pressure Symptoms (in Large Goitres)

Difficulty swallowing (dysphagia).
Difficulty breathing (dyspnea) due to tracheal compression.
Hoarseness of voice due to compression of the recurrent laryngeal nerve.

3. Thyroid Function Symptoms

Hyperthyroid goitre: Weight loss, palpitations, tremors, heat intolerance, irritability.
Hypothyroid goitre: Fatigue, weight gain, cold intolerance, constipation, depression.
Euthyroid goitre: Enlargement without hormonal symptoms.

4. Cosmetic Concerns

Visible swelling in the neck can affect appearance and self-esteem.

~Complications

Thyroid dysfunction: Hypothyroidism or hyperthyroidism.
Airway obstruction: In massive goitres.
Thyroid cancer: Risk increases in nodular goitre.
Thyrotoxicosis: Excess thyroid hormones, especially in toxic multinodular goitre.
Psychosocial impact: Cosmetic disfigurement can cause anxiety and low confidence.

~Diagnosis of Goitre

Diagnosis involves clinical evaluation, laboratory tests, and imaging studies.

1. History and Physical Examination

Duration, progression, family history, and associated symptoms.
Palpation of the thyroid for size, nodularity, and tenderness.

2. Laboratory Tests

Thyroid function tests: TSH, Free T4, Free T3.
Thyroid antibodies: To detect autoimmune thyroiditis.

3. Imaging Studies

Ultrasound: Determines size, nodules, and characteristics.
Radioactive iodine uptake scan: Differentiates between hyperfunctioning and hypofunctioning nodules.
CT/MRI: For large goitres extending into the chest (retrosternal goitre).

4. Fine Needle Aspiration Cytology (FNAC)

Helps rule out malignancy in nodules.

~Treatment of Goitre

Treatment depends on the size, symptoms, underlying cause, and presence of thyroid dysfunction.

1. Medical Treatment

Iodine supplementation: For iodine deficiency goitre.
Thyroid hormone replacement (Levothyroxine): For hypothyroid goitre.
Antithyroid drugs (Methimazole, PTU): For hyperthyroid goitre.
Beta-blockers: Symptom relief in hyperthyroidism.

2. Radioactive Iodine Therapy

Used for toxic multinodular goitre or Graves’ disease.
Destroys overactive thyroid tissue.

3. Surgical Treatment (Thyroidectomy)

Indicated for large goitres causing pressure symptoms, suspicion of cancer, or cosmetic reasons.
Types: Partial thyroidectomy, subtotal thyroidectomy, or total thyroidectomy.
Risks: Hypoparathyroidism, recurrent laryngeal nerve injury.

4. Observation (Watchful Waiting)

For small, asymptomatic, non-toxic goitres.
Regular follow-up with ultrasound and thyroid function tests.

~Goitre in Special Populations

1. Children

Often due to iodine deficiency or congenital thyroid disorders.
May affect growth and intellectual development.

2. Pregnant Women

Increased iodine requirement may lead to goitre.
Untreated thyroid disease can harm both mother and fetus.

3. Elderly

Multinodular goitre is common.
Higher risk of hyperthyroidism and cardiac complications.

~Prevention

Universal salt iodization: The most effective measure.
Balanced diet: Include iodine-rich foods such as fish, seaweed, dairy, and eggs.
Avoid goitrogens: Excessive consumption of cassava, millet, cabbage, and soy may worsen iodine deficiency.
Public health programs: Awareness campaigns and nutritional education.
Regular screening in high-risk populations.

~Global Burden of Goitre

According to the World Health Organization (WHO), over 2 billion people worldwide are at risk of iodine deficiency.
Endemic goitre remains a major public health problem in many developing countries, particularly in South Asia, Africa, and parts of Latin America.
In developed nations, autoimmune thyroid disorders are now the leading causes of goitre.

~Prognosis

With appropriate treatment, most cases of goitre have a good prognosis.
Iodine deficiency goitre responds well to supplementation.
Autoimmune goitre may require lifelong monitoring and treatment.
Large untreated goitres can cause complications, but timely surgery or radioiodine therapy provides relief.

~Conclusion

Goitre is a visible and often preventable manifestation of thyroid dysfunction. While its most common cause globally remains iodine deficiency, other causes such as autoimmune disorders, nodular disease, and malignancy also play important roles. Goitre can be asymptomatic or associated with thyroid dysfunction, and its clinical significance varies from minor cosmetic concerns to life-threatening complications.

Diagnosis involves careful clinical evaluation, thyroid function tests, imaging, and sometimes biopsy. Treatment ranges from simple iodine supplementation to medications, radioactive iodine therapy, or surgery, depending on the underlying cause and severity. Preventive measures, especially universal salt iodization and awareness programs, remain critical in reducing the global burden of goitre.

By understanding its causes, recognizing its signs early, and ensuring proper treatment, the impact of goitre on public health and individual quality of life can be significantly minimized.

Wednesday, September 3, 2025