Researchers have wondered for a long time whether there might be a link between excess thyroid hormone and an increased risk of breast cancer. High levels of thyroid hormone have been shown to mimic estrogen, which fuels many breast cancers. A new study has suggested that there may indeed be a link — but it’s important to put the results into context.
A slowdown in the output of the thyroid gland can cause many problems, ranging from extreme fatigue and depression to intolerance to cold, weight gain, dry skin, and dry hair. Millions of Americans have an underactive thyroid, a condition known as hypothyroidism. The symptoms can usually be controlled with a daily dose of synthetic thyroid hormone called levothyroxine. Who actually benefits from taking levothyroxine is being called into question. New evidence suggests that many people with borderline hypothyroidism may be taking this medication unnecessarily.
Japanese officials are preparing to distribute potassium iodide pills to people living near the nuclear power plants crippled by last week’s earthquake. Harvard Health Letter editor Peter Wehrwein explains what these pills do and who needs them.
The steam emitted by Japan’s failing nuclear reactors contains radioactive iodine-131. People living near the reactors can get substantial doses of iodine-131 by breathing the vapor from the reactors or ingesting iodine-131 from food or water. It accumulates in the thyroid gland, and significantly increases the risk of developing thyroid cancer.