Hypothyroidism

Hypothyroidism is usually treated with levothyroxine. This is a man-made version of thyroid hormone that you swallow.

• If your health care provider prescribes levothyroxine, tell them about all prescription and over-the-counter drugs, vitamins, and other supplements you take. Also let them know if you eat large amounts of certain foods, such as soy.

Levothyroxine can interact with certain medications. Soy, vitamins, other supplements, and both over-the-counter and prescription medications can all affect how your body responds to levothyroxine.

Your health care provider will start you on a low dose and slowly raise it as needed. Take this medicine on an empty stomach, at least one hour before taking any other drugs or supplements.

Tell your health care provider right away if you have any side effects. They will need to check your thyroid hormone levels on a regular basis.

In adults who have both dementia and hypothyroidism, thyroid replacement therapy may help improve thinking, daily function, and mood.

Hyperthyroidism Treatments

Anti-thyroid Medicines

Anti-thyroid medications can stop the thyroid from making too much hormone. These medicines do not work for everyone and may not work forever. They are usually tried first before considering radioactive iodine treatment.

Radioactive Iodine Therapy

This treatment involves swallowing radioactive iodine. The thyroid absorbs the iodine. Over time, the iodine shrinks the gland so it makes less hormone. Side effects are rare. After treatment, it can take up to 6 months for hormone levels to return to normal.

After treatment, your health care provider may need to lower the dose of your other medications. This is because your body may process those medications more slowly.

Sometimes, this treatment lowers your thyroid levels too much, and you develop hypothyroidism. If this happens, you will need to take medication for hypothyroidism every day.

Surgery

Thyroid surgery (thyroidectomy) removes most of the thyroid gland. It can be an option instead of radioactive iodine for some people. Risks include damage to the vocal cords and the parathyroid glands. The parathyroid glands help control calcium levels in the blood.

If you have this surgery, you will need to take synthetic thyroid hormone every day for the rest of your life.

Benign Nodules

If nodules are not cancerous and are not too big, your health care provider may simply watch them over time. If they keep growing, you may need another biopsy.

If the nodules cause problems, treatment may be needed. Surgery may be required if nodules make it hard to swallow or breathe. Nodules that make too much thyroid hormone may need radioactive iodine to shrink them, or an anti-thyroid medicine to lower hormone levels. If these do not work, surgery may be needed.

Cancerous Nodules

If a thyroid nodule is cancerous, surgery is usually needed. Most or all of the thyroid gland is removed. After surgery, you will need to take thyroid medication every day.

Levothyroxine Dose Levels

If your dose of levothyroxine is too high, you may have side effects such as:

• Increased appetite.
• Trouble sleeping.
• Heart palpitations (racing or fast heartbeat).
• Jitters or shakiness.

Your health care provider may need to lower your dose if you have any of these symptoms.

Tell your health care provider about any medications, supplements, or vitamins you take, because levothyroxine can interact with some of them. It can also interact with certain foods, like soy. Let your provider know about your diet and any big changes you make to it.

Never skip doses of levothyroxine or stop taking it. If you do, your symptoms will come back.

Last Reviewed and Updated: October 2026 
By: AGS/HiAF Public Education Committee, HealthinAging.org Content Reviewers