Goiter is an enlargement of the thyroid gland, which is manifested by swelling in the neck. If there is no nodule in the thyroid gland, the condition is called diffuse goiter; nodular goiter occurs when one or more nodules exist.
Non-nodular Goiter: When the thyroid gland does not secrete the thyroid hormone sufficiently, non-nodular goiter occurs. After thyroid hormones are not produced enough, the brain stimulates the thyroid gland to produce the hormone. The stimulated thyroid cells grow and proliferate to ensure necessary hormone secretion.
Nodular Goiter: The messages sent by the brain for further secretion of the thyroid hormones may, sometimes, provoke exaggerated response in certain cells of the thyroid gland and these cells proliferate more than others. This condition results in formation of lumps – nodules- in the thyroid gland.
Types of goiter and terms used:
Euthyroid (nontoxic) Goiter: The thyroid gland enlarges, but the hormone secretion does not vary.
Graves Disease (toxic goiter): The immune system perceives the thyroid cells as foreign. The system attacks the thyroid gland and the hormone secretion increases in the thyroid gland. This condition is called hyperthyroidism, or in other words “toxic goiter”.
Toxic multi-nodular goiter: A nodule or nodules in the thyroid gland may secrete the thyroid hormones in an uncontrolled manner and cause hyperthyroidism. The condition is common in elderly.
Pseudogoiter: Pseudogoiter occurs when the thyroid gland is located higher in the neck due to a congenital factor. The condition is prominent especially in those with thin neck. Examinations and ultrasound show normal thyroid gland and thus, goiter is ruled out.
Internal / External goiter: If the enlargement of the thyroid gland is visible, this condition is called external goiter. The condition is more common in slim individuals with thin and long neck. The enlarged gland is not visible in overweight individuals with short neck and this condition is called internal goiter.
Female goiter / male goiter: The goiter that relapses after surgery is called “female goiter”. In routine treatment, medication treatment is maintained after a part of the gland is removed surgically. In case medications are discontinued / interrupted, the body cannot outsource the hormone supply and therefore, TSH may be secreted excessively. Excessive hormone secretion stimulates the thyroid gland and causes relapse of the goiter. If complete cure is achieved in surgery and the goiter does not relapse in the postoperative course, this condition is colloquially called “male goiter”.
What are underlying causes of Goiter?
Iodine deficiency: It is the principal factor that causes goiter. Secretion of the thyroid hormone is dependent on the iodine. If sufficient amount of iodine is not taken from foods and water, the thyroid gland works too much and enlarges. Iodine deficiency-related goiter is usually confined to a certain region and this condition is common in regions of Turkey, where iodine intake is low.
Selenium deficiency: It is among the important minerals that affect functions of the thyroid hormone. Thyroid diseases follow a more severe course in case of iodine and selenium deficiencies.
Genetic predisposition: In case family history is notable for thyroid cancer, nodule or thyroid-related health problems, the risk of such conditions is higher.
Hyperthyroidism (Overactive thyroid gland): Hyperthyroidism occurs when the thyroid gland produces too much thyroid hormone even if serum level of thyroid hormones is within normal ranges.
Hypothyroidism (Underactive thyroid gland): Hypothyroidism implies poorly efficient functioning of the thyroid gland and failure to produce the thyroid hormone at expected level even when blood concentrations of thyroid hormones are low.
Nodules: The lumps inside or onto the thyroid gland are called nodule. The goiter resulting from abnormal enlargement of the thyroid gland due to nodules is called nodular goiter.
Thyroid cancer: Thyroid cancer may be detected especially in one or more nodules inside the gland. It may be detected incidentally or a swelling in the neck may indicate this condition.
Pregnancy and number of deliveries: Enlargement of the thyroid gland by half of its normal size in the absence of a disease is deemed a normal condition in pregnant women.
Smoking: Smoking may increase level of a substance that inhibits secretion of the thyroid hormone.
Moreover, inflamed thyroid gland and Vitamin A deficiency may also cause goiter.
Symptoms of Goiter
- Swelling in the neck
- Throat tightness
- Difficulty swallowing.
- Cough
- Hoarseness
- Shortness of breath
- Headache, dizziness, palpitation, shivering, bad temper, nausea, vomiting, diarrhea (when the thyroid hormone is secreted too much)
- Weight gain, constipation, fatigue, dry skin, hair loss (when the thyroid hormone is secreted too low)
Risk group for goiter
- Family history of thyroid cancer, nodule or thyroid-related health problems
- Insufficient iodine intake
- Other conditions that lead to iodine deficiency in the body
- The risk of goiter is higher in women than men
- Prevalence increases after the age of 40
- Pregnancy
- Menopause
- Radiotherapy for the neck or chest
Diagnosis of goiter
If you notice an abnormality in your body, especially a palpable swelling in your neck, we recommended you visit a specialist within the shortest possible time. The diagnosis of goiter is verified with physical examination, thyroid hormone tests and ultrasound. If necessary, your doctor may evaluate results of fine needle biopsy and scintigraphy.
Treatment of goiter
Following methods are commonly used for treatment of goiter:
- Medication therapy
- Radioactive iodine therapy
- Surgical treatment
If body of the patient secretes the hormone poorly, hormone replacement is considered, or if too much hormone is produced, the hormone level is normalized with drugs that suppress secretion of the hormone. Moreover, a surgical procedure or radioactive iodine therapy can be planned, if deemed necessary. Surgical treatment is considered in patients with nodule whose hormone levels are within normal ranges. The thyroid gland is removed completely or partially. It is aimed to avoid damage to the neighboring tissues and vocal cords in the surgery.
The link between goiter and cancer
Thyroid nodules can easily be managed and controlled with medications. The risk of cancer may be present in 5% of all patients. Thus, it is important to attend follow-up exams regularly.