Hypothyroidism is treated with medication. Most people report feeling better within days to weeks of beginning treatment.
NYU Langone doctors treat people with hypothyroidism using a synthetic form of thyroxine, or T4—the hormone the thyroid produces insufficiently—called levothyroxine. It may be needed only for a short time if hypothyroidism is caused by a temporary condition, such as some forms of thyroiditis.
In people who have permanent conditions, such as Hashimoto’s thyroiditis or the removal of all or part of the thyroid gland—called thyroidectomy—levothyroxine is prescribed for life. Your doctor determines the dose based on follow-up blood tests. It’s taken daily by mouth.
Most people easily tolerate levothyroxine. In fact, many report feeling better within just one week of beginning treatment.
If you have heart disease, your doctor may start you on a lower dose of levothyroxine, increasing it slowly while monitoring you. Too much of this medication can increase heart rate and the risk of arrhythmia, especially in older people, and contribute to bone loss.
Whether you’ve just started treatment or have been taking levothyroxine for years, it’s important that you have your thyroid-stimulating hormone, or TSH, level monitored every six months—or more often if the level isn’t where it should be. Be sure to tell your doctor about any changes in your symptoms, so that he or she can repeat thyroid tests and adjust the dose as necessary.
Doctors typically advise treatment if the TSH level remains elevated and doesn’t resolve on its own or if symptoms are significant. If your blood test shows a mildly elevated TSH level, your doctor may not recommend treating it immediately. Instead, your doctor may observe TSH levels for some time before prescribing medication.