Thyroid Diseases

The Thyroid Gland and Its Functions

The thyroid gland is stimulated by TSH (Thyroid-Stimulating Hormone) secreted by the pituitary gland and produces T3 (triiodothyronine) and T4 (thyroxine) hormones. These hormones:

• Regulate metabolic rate
• Affect the function of the heart and digestive system
• Contribute to brain development and cognitive function
• Control body temperature and energy production
• Support bone development and muscle health
• Are critical for growth and development during childhood

Main Types of Thyroid Diseases

Hypothyroidism (Underactive Thyroid)

A condition in which the thyroid gland does not produce enough hormones. The most common cause is Hashimoto's disease (autoimmune thyroiditis), a chronic inflammatory condition resulting from the body producing antibodies against its own thyroid cells.

Symptoms:

• Fatigue and weakness
• Unexplained weight gain
• Cold intolerance
• Constipation
• Hair loss and dry skin
• Depressive symptoms
• Menstrual irregularities
• Memory and concentration problems

Hyperthyroidism (Overactive Thyroid)

A condition in which thyroid hormones are produced in greater amounts than normal. The most common cause is Graves' disease. Toxic nodules or toxic multinodular goiter may also cause hyperthyroidism.

Symptoms:

• Palpitations and rapid heart rate
• Unexplained weight loss
• Excessive sweating
• Hand tremors
• Heat intolerance
• Nervousness and restlessness
• Sleep disturbances
• Protruding eyes (in Graves' disease)

Thyroid Nodules

Lumps or masses that develop in the thyroid gland. They are quite common in the population, and most are benign. However, since 5-10% may carry a risk of cancer, every nodule should be evaluated. They are often discovered incidentally during ultrasound.

Goiter

Defined as the enlargement of the thyroid gland. It can develop due to iodine deficiency, autoimmune diseases, or nodules. Large goiters may cause difficulty in breathing and swallowing.

Thyroid Cancer

A malignant disease of the thyroid gland. It has four main types:

• Papillary thyroid cancer: The most common type, slow-growing
• Follicular thyroid cancer: The second most common
• Medullary thyroid cancer: May be hereditary
• Anaplastic thyroid cancer: Rare but aggressive

When diagnosed early, particularly in papillary and follicular types, treatment success rates are quite high.

Thyroiditis

Inflammation of the thyroid gland. Hashimoto's thyroiditis, subacute thyroiditis, and postpartum thyroiditis are the most common types.

Diagnostic Methods

Various methods are used to diagnose thyroid diseases:

Blood Tests

• TSH: The basic test to evaluate thyroid function
• Free T3 and T4: Show active hormone levels
• Anti-TPO and Anti-Tg antibodies: Used to diagnose autoimmune thyroid diseases
• Thyroglobulin: An important marker in thyroid cancer follow-up
• Calcitonin: Used in medullary thyroid cancer screening

Imaging Methods

• Thyroid ultrasound: Evaluation of the gland's structure, size, and nodules
• Thyroid scintigraphy: Functional mapping of the gland
• CT or MRI: For evaluating large goiters and invasive cancer

Fine Needle Aspiration Biopsy (FNAB)

A cellular evaluation performed by taking a sample from suspicious thyroid nodules. It is performed in most cases before a surgical decision is made.

Treatment Methods

Treatment of thyroid diseases varies depending on the underlying condition:

Medication Treatment

• Levothyroxine: The main medication in the treatment of hypothyroidism
• Antithyroid drugs (propylthiouracil, methimazole): Used in the treatment of hyperthyroidism
• Beta blockers: To manage hyperthyroidism symptoms
• Radioactive iodine therapy: Can be applied in the treatment of hyperthyroidism and thyroid cancer

Surgical Treatment

Surgical treatment may be required in the following cases:

• Thyroid cancer or suspicion of cancer
• Large goiter (causing pressure symptoms)
• Hyperthyroidism unresponsive to medication
• Suspicious or continuously growing nodules
• Cosmetic reasons

Thyroid Surgery (Thyroidectomy)

Types of Surgery

Total thyroidectomy: The removal of the entire thyroid gland. Preferred in cases of cancer and large goiter.

Hemithyroidectomy (lobectomy): The removal of only one lobe of the thyroid gland. May be applied in unilateral nodule or small cancer cases.

Neck dissection: An additional procedure performed when lymph node removal is needed in thyroid cancer.

The Surgical Process

The procedure is performed under general anesthesia through an approximately 4-6 cm incision in the neck. In modern thyroid surgery:

• Nerve monitors are used to protect the vocal cords
• The parathyroid glands are carefully separated
• A thin incision placed in a skin fold is preferred for aesthetic reasons
• The operation duration is generally 1-2 hours

Post-Operative Process

• Hospital stay is generally 1-2 days
• Mild swelling and tenderness in the neck may last for a few weeks
• After total thyroidectomy, lifelong levothyroxine treatment is required
• Calcium and vitamin D levels are closely monitored
• Vocal cord and swallowing function are evaluated
• Most patients return to daily life within 1-2 weeks

Possible Risks

Like any surgical procedure, thyroidectomy carries certain risks:

• Temporary or permanent vocal cord weakness
• Effects on the parathyroid glands (low calcium)
• Bleeding or hematoma formation
• Wound infection
• Anesthesia-related complications

When performed by experienced teams, the rate of serious complications is low.

Lifestyle in Thyroid Diseases

To support the treatment process:

• Attending regular check-ups
• Not interrupting medication treatment
• Eating a balanced diet (iodine-containing foods)
• Stress management
• Adequate and quality sleep
• Regular physical activity
• Avoiding smoking and alcohol