Hyperthyroidism is a condition in which the thyroid gland is overactive and makes excessive amounts of thyroid hormone. The thyroid gland is an organ located in the front of your neck and releases hormones that control your metabolism (the way your body uses energy), breathing, heart rate, nervous system, weight, body temperature, and many other functions in the body. When the thyroid gland is overactive (hyperthyroidism) the body’s processes speed up and you may experience nervousness, anxiety, rapid heartbeat, hand tremor, excessive sweating, weight loss, and sleep problems, among other symptoms.
- Hyperthyroidism is a condition in which there is an excessive amount of thyroid hormones.
- Thyroid hormones regulate the metabolism of the cells.
- Normally, the rate of thyroid hormone production is controlled by the brain at the pituitary gland.
- There are many possible causes of hyperthyroidism.
- Common symptoms of hyperthyroidism include restlessness, tremors, weight loss despite an increased appetite, sweating, rapid heart rate, intolerance to heat, and frequent bowel movements.
- Treatments for hyperthyroidism include medications, ablation, and surgery.
A variety of conditions can cause hyperthyroidism. Graves’ disease, an autoimmune disorder, is the most common cause of hyperthyroidism. It causes antibodies to stimulate the thyroid to secrete too much hormone. Graves’ disease occurs more often in women than in men. It tends to run in families, which suggests a genetic link. You should tell your doctor if your relatives have had the condition.
Other causes of hyperthyroidism can include:
- excess iodine, a key ingredient in T4 and T3
- inflammation of the thyroid (thyroiditis) that causes T4 and T3 to leak out of the gland
- tumors of the ovaries or testes
- benign tumors of the thyroid or pituitary gland
- large amounts of tetraiodothyronine taken through dietary supplements or medication
Hyperthyroidism can mimic other health problems, which may make it difficult for your doctor to diagnose. It can also cause a wide variety of signs and symptoms, including:
- Sudden weight loss, even when your appetite and the amount and type of food you eat remain the same or even increase
- Rapid heartbeat (tachycardia) commonly more than 100 beats a minute irregular heartbeat (arrhythmia) or pounding of your heart (palpitations)
- Increased appetite
- Nervousness, anxiety and irritability
- Tremor — usually a fine trembling in your hands and fingers
- 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 your neck
- Fatigue, muscle weakness
- Difficulty sleeping
- Skin thinning
- Fine, brittle hair
Older adults are more likely to have either no signs or symptoms or subtle ones, such as an increased heart rate, heat intolerance and a tendency to become tired during ordinary activities. Medications called beta blockers, which are used to treat high blood pressure and other conditions, can mask many of the signs of hyperthyroidism.
Treatment depends on the cause and severity of symptoms. Hyperthyroidism is usually treated with one or more of the following:
- Antithyroid medicines (propylthiouracil or methimazole)
- Radioactive iodine to destroy the thyroid gland and stop the excess production of hormones
- Surgery to remove the thyroid
If your thyroid is removed with surgery or destroyed with radioactive iodine, you must take thyroid hormone replacement pills for the rest of your life.
Medicines called beta-blockers may be prescribed to treat symptoms such as fast heart rate, tremor, sweating, and anxiety until the hyperthyroidism can be controlled