Graves’ disease is a common thyroid disorder, with an incidence rate of approximately 1% in Hong Kong, and it predominantly affects women.

Causes

The secretion of thyroid hormones is influenced by thyroid-stimulating hormone (TSH). Under normal circumstances, TSH is secreted by the pituitary gland, travels through the bloodstream to the thyroid gland, and stimulates the TSH receptors on the surface of thyroid cells, thereby instructing the thyroid cells to produce and release thyroid hormones.

In individuals with Graves’ disease, their immune system malfunctions and produces a large number of antibodies that target the TSH receptors. When these immune antibodies bind to the TSH receptors, it directly stimulates the thyroid cells to produce and secrete thyroid hormones (T4). Since thyroid hormones primarily control the metabolic functions of various organs in the body, the uncontrolled secretion of thyroid hormones leads to an accelerated metabolism in the patient’s organs. This, in turn, results in symptoms such as rapid heartbeat, tremors, and weight loss.

Graves’ disease is associated with multiple factors:

• Family history: There is a certain relationship between Graves’ disease and genetic and familial factors. According to statistics, relatives of individuals with Graves’ disease have a 9 to 20 times higher risk of developing the condition compared to individuals without a family history. This may involve genes that partially control the immune system or thyroid cell surface receptors.
• Abnormal immune system: Graves’ disease occurs when the immune system malfunctions and produces a large number of antibodies that target the TSH receptors. This indirect stimulation leads to the secretion of thyroid hormones (T4), and the uncontrolled secretion causes an accelerated metabolism in various organs of the body, resulting in symptoms of hyperthyroidism. In addition, individuals with other autoimmune diseases such as systemic lupus erythematosus or rheumatoid arthritis also have an increased risk of developing thyroid disorders.

Hyperthyroidism

Patients with hyperthyroidism experience an excessive secretion of thyroid hormones, resulting in accelerated metabolism. Symptoms of hyperthyroidism include:

• Rapid heartbeat, palpitations
• Irritability, mood swings
• Depression
• Insomnia
• Increased appetite but noticeable weight loss
• Menstrual irregularities
• Diarrhea, frequent bowel movements

Goiter (Enlarged Thyroid)

The enlargement of the thyroid gland in the neck is known as a goiter. In Graves’ disease, the goiter is usually symmetrical and caused by inflammation and swelling of the thyroid gland, which is located in front of the trachea in the neck.

Exophthalmos (Bulging Eyes)

Patients with Graves’ disease may develop exophthalmos, commonly known as bulging eyes. This occurs due to the autoimmune system producing antibodies that attack the muscles surrounding the eyes, affecting their contraction and causing the eyes to protrude.

Blood Test: Thyroid Function Tests

Thyroid function tests evaluate the secretion of thyroid hormones in the body and can be determined through blood tests. Thyroid function tests include measurements of triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) levels. These tests help doctors distinguish between hyperthyroidism, hypothyroidism, or normal thyroid hormone secretion.

Clinical Examination

Through physical examination and clinical assessment, doctors can inquire about the patient’s medical history, family history, and related symptoms. Clinical palpation allows the doctor to determine if the patient has thyroid enlargement, the symmetry and uniformity of the thyroid swelling, the presence of other nodules or lymph node enlargement in the neck, and whether the trachea is compressed by thyroid swelling. After the initial evaluation, the doctor may arrange further examinations such as thyroid ultrasound or thyroid fine-needle aspiration.

Thyroid Ultrasound

Thyroid ultrasound is a non-invasive examination. During the procedure, the doctor applies gel to the patient’s neck and uses an ultrasound probe to obtain real-time images of the thyroid. The doctor captures corresponding images during the examination for evaluation. Thyroid ultrasound helps the doctor assess the size of the thyroid, the size and nature of thyroid nodules, the blood flow around the nodules, the identification of calcifications, the differentiation of thyroid cysts and nodules, and the evaluation of lymph node enlargement in the neck.

Other Tests

Additional tests may include computerized tomography (CT) scans, chest X-rays, electrocardiograms (ECG).

Thyroid storm can be life-threatening. It occurs when a patient’s hyperthyroidism is not properly treated or uncontrolled, and they are exposed to various external triggers such as trauma, infection, or surgery, among others.

Symptoms of thyroid storm include high fever, rapid heartbeat, high blood pressure, nausea, enlarged liver, jaundice, restlessness, and whole-body tremors. Without appropriate medical intervention, complications such as mental confusion, coma, arrhythmias, or heart failure can occur, leading to potential fatalities.

In addition to the risk of thyroid storm, patients with hyperthyroidism may also experience the following complications:

• Eye complications: Prolonged eye protrusion can lead to incomplete eyelid closure, corneal damage, and even optic nerve impairment resulting in blindness.
• Psychiatric complications: Emotional instability, nervousness, insomnia, agitation, or depression are common psychiatric complications associated with hyperthyroidism.
• Metabolic disorders: Hyperthyroidism can trigger conditions like diabetes or liver dysfunction.
• Digestive problems: Patients may experience frequent diarrhea and indigestion.
• Osteoporosis: Excessive thyroid hormone secretion accelerates bone breakdown, leading to osteoporosis and an increased risk of fractures.
• Cardiac failure: Prolonged elevated heart rate and irregular heart rhythms can eventually lead to cardiac failure and other heart-related complications.
• Infertility and miscarriage: Hyperthyroidism increases the risk of infertility, miscarriage, and premature delivery in women.

It’s important for individuals with hyperthyroidism to receive appropriate medical care and management to prevent these potential complications.

Medication Therapy

Medication is the primary method of treating Graves’ disease. Doctors prescribe anti-thyroid medications that work by suppressing the production and effectiveness of thyroid hormones, thereby restoring normal thyroid function and metabolism. Patients need close monitoring of their thyroid hormone levels when starting medication. Generally, patients need to take medication for at least one and a half to two years until their own thyroid function returns to normal before considering discontinuation. About 50% of people achieve remission after stopping the medication, but some may experience relapses or recurrent episodes.

A small percentage of patients may experience allergic reactions to the medication, such as itching or rash. Other possible complications include temporary liver dysfunction. In such cases, patients may need to switch to alternative medications or consider other treatment options.

Surgical Management

When a patient has a visibly enlarged thyroid gland affecting appearance or experiences recurrent or uncontrolled Graves’ disease, the doctor may recommend thyroidectomy (surgical removal of the thyroid gland).

Generally, doctors suggest total thyroidectomy for patients with Graves’ disease. The surgery is performed under general anesthesia, and the incision is typically hidden within natural neck creases to minimize visible scarring.

Total thyroidectomy involves the complete removal of the thyroid gland. Since the thyroid gland is responsible for producing thyroid hormones, patients require daily thyroid hormone replacement therapy after surgery to maintain adequate thyroid levels. The total thyroidectomy procedure takes about two hours.

Radioactive Iodine Therapy

Radioactive iodine therapy involves the use of a radioactive iodine solution to selectively destroy some thyroid cells. It is primarily used to treat hyperthyroidism. Due to the thyroid’s ability to absorb and concentrate iodine, the radioactive iodine is taken up by the thyroid gland, releasing radiation that kills some of the thyroid cells, thereby reducing hormone production and secretion. Typically, patients only need to take radioactive iodine once or a few times to resolve hyperthyroidism. This treatment method is cost-effective and straightforward. However, it is not suitable for pregnant women or patients with eye complications.