To begin the conversation about Hyperthyroidism it would only be right to start by giving you an idea what the thyroid gland is.
The thyroid gland is a small butterfly-shaped gland located at the front of the neck. It produces tetraiodothyronine (T4) and triiodothyronine (T3). These two hormones are essential in controlling metabolism which is the process by which the body utilizes energy. It also affects your heart, muscles, bones, and cholesterol.
Hyperthyroidism therefore occurs when too much T4 and/or T3 is produced.
Causes of hyperthyroidism
Hyperthyroidism has several causes. The most common one is Graves’ disease.
It is an auto immune disorder in which antibodies stimulate the thyroid to secrete too much hormone. It occurs more often in women and tends to run in families.
Other causes of hyperthyroidism include:
- excess iodine (iodine is needed to make T4 and T3)
- inflammation of the thyroid gland (thyroiditis causes T4 and T3 to leak out of the gland)
- certain tumors of the ovaries or testes
- benign tumors of the thyroid or pituitary gland
- taking large amounts of tetraiodothyronine (T4) (through dietary supplements or medication)
Signs and Symptoms
Hyperthyroidism causes a wide variety of signs and symptoms, due to the fact that the thyroid hormones control metabolism, excess of these hormones would cause an state of increased metabolism. This can lead to manifestations such as
- Sudden weight loss, even when appetite and the amount and type of food eaten remains the same or even increase
- Rapid/irregular heartbeat or pounding of your heart (palpitations)
- Increased appetite
- Nervousness, anxiety and irritability
- Tremor — usually a fine trembling in the hands and fingers
- Sweating
- Changes in menstrual patterns
- Increased sensitivity to heat
- Changes in bowel patterns, especially more frequent bowel movements
- An enlarged thyroid gland (goiter), which may appear as a swelling at the base of the neck
- Fatigue, muscle weakness
- Difficulty sleeping
- Skin thinning
- Fine, brittle hair
Hyperthyroidism can also cause atrial fibrillation, a dangerous arrhythmia that can cause strokes. Congestive heart failure may also occur. It is important to seek medical care immediately if you notice constant dizziness, shortness of breath, loss of consciousness, or fast irregular heart rate
Diagnosis
In order to make a diagnosis of hyperthyroidism the doctor will first have to take a detailed history from the patient and conduct a detailed physical examination looking out for he signs listed above. In addition some laboratory tests will also have to be carried out. These are:
- A thyroid-stimulating hormone (TSH) test, which is a blood test that measures the levels of TSH which is usually reduced when there is excess T3 and T4.
- Thyroid hormone tests, which are blood tests to measure the levels of two types of thyroid hormones, called T3 and T4. High levels are indicative of hyperthyroidism.
These are also tested continuously when treatment is commenceed to monitor the effectiveness of treatment.
After a diagnosis of hyperthyroidism is made, the doctor may also want to do:
- An antithyroid antibody test. This test can help diagnose Graves’ disease and autoimmune thyroiditis.
- A radioactive thyroid scan and radioactive iodine uptake tests, which use radiation and a special camera to find out the cause of the hyperthyroidism.
Treatment
Several treatments for hyperthyroidism exist. Choice of treatment depends on the patients age, physical condition and the severity of the disorder.
Radioactive iodine. Taken by mouth, radioactive iodine is absorbed by the thyroid gland, where it causes the gland to shrink and destroys the thyroid producing cells effectively causing symptoms to subside, usually within three to six months. This treatment may also cause the thyroid gland to be underactive (hypothyroidism), and thyroxine replacement may become necessary.
Anti-thyroid medications. These medications gradually reduce symptoms of hyperthyroidism by preventing the thyroid gland from producing excess amounts of hormones. They include propylthiouracil and methimazole (Tapazole). Symptoms usually begin to improve in six to 12 weeks, but treatment with anti-thyroid medications typically continues at least a year and often longer.
Beta blockers. These drugs are commonly used to treat high blood pressure. They do act on the thyroid but they can reduce a rapid heart rate and help prevent palpitations which are usually troubling symptoms for people with hyperthyroidism.
Surgery (thyroidectomy).
Sometimes, a portion or all of the thyroid gland may have to be surgically removed. When this happens, thyroid hormone supplements must be taken to prevent hypothyroidism. This is usually as a last resort when patients are either unable to tolerate other treatments or the treatments are no longer working.
