What is Thyroid Disorder?
The thyroid is a gland located in the front of the neck. It produces thyroid hormones, which regulate various vital metabolic processes including growth and energy consumption. The thyroid can become overactive leading to hyperthyroidism, or underactive leading to hypothyroidism.
- The most common cause of hyperthyroidism is Graves’ disease, in which the immune system produces antibodies that bind to the surface of thyroid cells and abnormally stimulate those cells to overproduce thyroid hormones. The same antibodies also cross react with the soft tissue behind the eyes, leading to eye irritation, swelling, and in severe cases, vision problems. The causes of Graves’ disease are not yet fully understood, but genetics is commonly believed to be a risk factor.
- Toxic thyroid nodule, an abnormal growth of thyroid cells that forms a lump in the thyroid gland and secretes an excessive amount of thyroid hormones.
- Inflammation of the thyroid gland, known as thyroiditis, can also lead to hyperthyroidism.
The most likely causes are the loss of function of the thyroid gland secondary to autoimmunity destruction (Hashimoto thyroiditis), destruction by inflammation (de Quervain thyroiditis) or destruction due to previous treatment (radioactive iodine or surgical removal of the thyroid gland).
Symptoms of hyperthyroidism include:
- Anxiety, nervousness and irritability
- Fast heart rate and palpitations (can lead to heart failure)
- Sensitivity to heat
- Weight loss
- Difficulties in sleeping
- Bulging eyes
- Changes in menstruation
- Fatigue and lethargy
- Muscle weakness and trembling
Symptoms of hypothyroidism include:
- Slow heart rate
- Weight gain
- Sensitivity to cold
- Changes in menstruation
- Fatigue and sluggishness
- Muscle pain and weakness
- Fragile fingernails and hair
- Pale skin and puffy face
Treatment of hyperthyroidism depends on the patient’s age, physical status, and specific cause and severity of patient’s condition. Treatment options include:
- Anti-thyroid medicine: to block the secretion of thyroid hormones and gradually alleviate symptoms. Often chosen as first-line treatment due to convenience. Treatment is usually given for 18-24 months. A significant number of patients experience relapse after the medicine is stopped.
- Radioactive iodine treatment: is used if the response to anti-thyroid medications is not good or if the patient so chooses. Radioactive iodine is administered orally and is absorbed into the bloodstream and uptaken by the thyroid gland. The radioactivity ablates part or all of the thyroid gland to reduce the thyroid activity permanently. Life-long medication may eventually be required to maintain normal thyroid hormone levels.
- Surgical removal: most invasive, but may be necessary in some case especially if the there is a much enlarged thyroid (i.e. goitre) with risk of airway compression, suspicion of cancerous changes after ultrasound assessment or if there is severe eye disease. Life-long medication is often required to maintain normal thyroid hormone levels after surgery.
- Hormone replacement therapy: aims at regulating thyroid hormone levels by using a synthetic thyroid hormone pill
- Eye problems such as bulging eyes and blurred vision (caused by Graves’ disease)
- Fever and hallucinations
- Irregular heart rhythm and heart failure
- Osteoporosis, a disease of weak and brittle bones