Hyperthyroidism
Source: MedlinePlus Health Topics, U.S. National Library of Medicine
What is hyperthyroidism? Hyperthyroidism, or overactive thyroid, happens when your thyroid gland makes more thyroid hormones than your body needs. Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods. If not treated, hyperthyroidism can cause serious problems with your heart, bones, muscles, menstrual cycle, and fertility. But there are treatments that can help. What causes hyperthyroidism? Hyperthyroidism has several causes. They include: Graves' disease, an autoimmune disorder in which your immune system attacks your thyroid and causes it to make too much hormone. This is the most common cause. Thyroid nodules, which are growths on your thyroid. They are usually benign (not cancer). But they may become overactive and make too much thyroid hormone. Thyroid nodules are more common in older adults. Thyroiditis, inflammation of the thyroid. It causes stored thyroid hormone to leak out of your thyroid gland. Too much iodine. Iodine is found in some medicines, cough syrups, seaweed and seaweed-based supplements. Taking too much of them can cause your thyroid to make too much thyroid hormone. Too much thyroid medicine. This can happen if people who take thyroid hormone medicine for hypothyroidism (underactive thyroid) take too much of it. Who is at risk for hyperthyroidism? You are at higher risk for hyperthyroidism if you: Are a woman Are older than age 60 Have been pregnant or had a baby within the past 6 months Have had thyroid surgery or a thyroid problem, such as goiter Have a family history of thyroid disease Have pernicious anemia , in which the body cannot make enough healthy red blood cells because it does not have enough vitamin B12 Have type 1 diabetes or primary adrenal insufficiency, a