High thyroid levels, or hyperthyroidism, is most commonly caused by Graves’ disease, but can also be caused by multinodular or toxic nodular goiters, excess consumption of iodine or medications that contain iodine, according to EndocrineWeb. More rarely, pregnant women or women who recently gave birth may also develop hyperthyroidism.
Graves’ disease is an autoimmune disorder in which the body produces an antibody known as thyroid-stimulating immunoglobulin that causes an overproduction of thyroid hormone in the thyroid gland, according to EndocrineWeb. Graves’ disease is more common in women and tends to run in families. It is the leading cause of hyperthyroidism.
Symptoms of hyperthyroidism include weight loss, trouble sleeping, muscle weakness, fatigue and mood swings, notes EndocrineWeb. Hand tremors, anxiety, nervousness, rapid or irregular heartbeat, or heart palpitations can also be symptomatic of elevated thyroid levels. Other symptoms include trouble sleeping, skin dryness, skipping or having light menstrual periods, and increased bowel movement frequency.
Treatment for hyperthyroidism generally involves the administration of medications that disrupt thyroid hormone production, including methimazole, advises EndocrineWeb. Radioactive iodine therapy may also be an option, as this treatment damages the cells responsible for producing thyroid hormone. More severe or stubborn cases of hyperthyroidism may require the partial or complete removal of the thyroid gland.