What is Goitre?
A goitre is an abnormal enlargement of the thyroid gland, which is located at the front of the neck. This condition can occur due to various reasons—hormonal imbalances, autoimmune diseases, iodine deficiency, or tumors. Importantly, a goitre itself is not a disease but a clinical sign pointing to underlying thyroid dysfunction.
Thyroid Gland Function & Hormones
The thyroid gland produces two critical hormones:
- Thyroxine (T4)
- Triiodothyronine (T3)
These hormones regulate:
- Metabolism
- Heart rate
- Temperature control
- Brain function
- Digestion
The release of T3 and T4 is controlled by Thyroid Stimulating Hormone (TSH) from the pituitary gland, which is in turn regulated by the hypothalamus.
Causes of Goitre
Goitre can be physiological or pathological. Here's a breakdown:
Physiological Causes
- Puberty
- Pregnancy
- Increased hormone demand
Pathological Causes
- Iodine deficiency: Most common global cause
- Graves’ disease: Autoimmune hyperthyroidism
- Hashimoto’s thyroiditis: Autoimmune hypothyroidism
- Pituitary adenomas or failure
- Thyroid nodules: Benign or malignant
- Congenital enzyme deficiencies
Types of Goitre
Goitres are categorized based on hormone production and pathology:
Euthyroid Goitre
- Normal thyroid function
- Common in early iodine deficiency
Toxic Goitre
- Produces excess hormones
- Seen in Graves’ disease, Plummer’s disease
Nontoxic Goitre
- Enlarged gland without hormone imbalance
- Often due to iodine deficiency
Hyperthyroidism vs Hypothyroidism
Hyperthyroidism (Overactive Thyroid)
Causes:
- Graves’ disease
- Toxic multinodular goitre
- Thyroid adenoma
- Secondary: Pituitary adenoma
Symptoms:
- Heat intolerance
- Weight loss
- Sweating
- Tremors
- Palpitations
- Diarrhoea
- Anxiety, excitement
- Exophthalmos (bulging eyes)
Signs:
- Lid lag, lid retraction
- Atrial fibrillation
- Hyperreflexia
- Pre-tibial myxoedema
Hypothyroidism (Underactive Thyroid)
Causes:
- Hashimoto’s thyroiditis
- Pituitary or hypothalamic failure
- Congenital enzyme defect
Symptoms:
- Cold intolerance
- Weight gain
- Constipation
- Depression, tiredness
- Hoarseness
Signs:
- Puffy face, eyelids
- Hair loss, thin eyebrows
- Dry skin
- Bradycardia
- Peripheral oedema
Clinical Features & Body System Involvement
| System | Hyperthyroidism | Hypothyroidism |
|---|---|---|
| CNS | Excitement, tremors, poor concentration | Lassitude, slow mentation |
| Skin | Sweaty, flushed | Coarse dry skin, pallor |
| GI | Diarrhoea | Constipation |
| CV | Tachycardia, high pulse pressure | Bradycardia, hypotension |
| Eye | Exophthalmos, lid lag | Puffy eyelids |
| Muscle | Hyperreflexia | Proximal myopathy, hyporeflexia |
Diagnostic Tests & Investigations
Hormonal Assays
- TSH
- Free T3, Free T4
- Anti-thyroid antibodies (e.g., TPOAb in Hashimoto’s)
Imaging
- Ultrasound: Detect nodules or cysts
- Radioactive Iodine Uptake Scan (I¹²³): Evaluates functional status
- CT/MRI: In large or retrosternal goitres
FNAC (Fine Needle Aspiration Cytology)
- Essential for solitary nodules
- Helps exclude malignancy
Management & Treatment Options
Hyperthyroidism
- Medical: Antithyroid drugs (carbimazole), beta-blockers (propranolol), radioactive iodine
- Surgical: Subtotal thyroidectomy (if refractory to medical therapy or for cosmetic reasons)
Hypothyroidism
- Thyroid hormone replacement therapy: Levothyroxine
- Regular monitoring of TSH levels
Nodular Goitre
- <4 cm and benign: Reassure
- >4 cm or suspicious: Lobectomy or total thyroidectomy
Thyroid Malignancy
- Papillary carcinoma: Total thyroidectomy + radioactive iodine
- Long-term follow-up with thyroglobulin levels
FAQs on Goitre
Q1. Is goitre always due to iodine deficiency?
No, while it's a common cause worldwide, goitre can also result from autoimmune diseases, tumors, and hormonal imbalances.
Q2. Can goitre occur without symptoms?
Yes, early-stage goitre may be asymptomatic and detected during routine examination.
Q3. Is surgery always required?
No, surgery is reserved for cosmetic concerns, malignancy suspicion, or failure of medical therapy.
Q4. How to prevent goitre?
- Adequate iodine intake
- Early screening in high-risk individuals
- Monitoring thyroid function during pregnancy
Q5. What foods help or hurt thyroid health?
- Helpful: Iodized salt, dairy, fish, eggs
- Harmful (in excess): Soy, cruciferous vegetables (if iodine-deficient), highly processed foods
Conclusion
Goitre is a visible sign of thyroid dysfunction that warrants thorough investigation. Whether stemming from hyperthyroidism, hypothyroidism, or iodine deficiency, early diagnosis and appropriate treatment can significantly improve quality of life. As thyroid disorders continue to rise globally, raising awareness and ensuring accessible care is essential.
