Hyperthyroidism is diagnosed using:
- Medical history and physical exam. During the exam your doctor may try to detect a slight tremor in your fingers when they're extended, overactive reflexes, eye changes and warm, moist skin. Your doctor will also examine your thyroid gland as you swallow to see if it's enlarged, bumpy or tender and check your pulse to see if it's rapid or irregular.
Blood tests. Blood tests that measure thyroxine and thyroid-stimulating hormone (TSH) can confirm the diagnosis. High levels of thyroxine and low or nonexistent amounts of TSH indicate an overactive thyroid. The amount of TSH is important because it's the hormone that signals your thyroid gland to produce more thyroxine.
These tests are particularly necessary for older adults, who may not have classic symptoms of hyperthyroidism.
Thyroid blood tests may give false results if you're taking biotin — a B vitamin supplement that may also be found in multivitamins. Let your doctor know if you are using biotin or a multivitamin with biotin. To ensure an accurate test, stop taking biotin at least 12 hours before blood is taken.
If blood tests indicate hyperthyroidism, your doctor may recommend one of the following tests to help determine why your thyroid is overactive:
Radioiodine uptake test. For this test, you take a small, oral dose of radioactive iodine (radioiodine) to see how much will collect in your thyroid gland. You'll be checked after four, six or 24 hours — and sometimes after all three time periods — to see how much iodine your thyroid has absorbed.
A high uptake of radioiodine indicates your thyroid gland is producing too much thyroxine. The most likely cause is either Graves' disease or hyperfunctioning thyroid nodules. If you have hyperthyroidism and your radioiodine uptake is low, this indicates that the thyroxine stored in the gland is leaking into the bloodstream, which may mean you have thyroiditis.
- Thyroid scan. During this test, you'll have a radioactive isotope injected into the vein on the inside of your elbow or sometimes into a vein in your hand. You then lie on a table with your head stretched backward while a special camera produces an image of your thyroid gland on a computer screen. This test shows how iodine collects in your thyroid.
- Thyroid ultrasound. This test uses high-frequency sound waves to produce images of the thyroid. Ultrasound may be better at detecting thyroid nodules than other tests, and there's no exposure to any radiation.
Several treatments for hyperthyroidism exist. The best approach for you depends on your age, physical condition, the underlying cause of the hyperthyroidism, personal preference and the severity of your disorder. Possible treatments include:
Radioactive iodine. Taken by mouth, radioactive iodine is absorbed by your thyroid gland, where it causes the gland to shrink. Symptoms usually subside within several months. Excess radioactive iodine disappears from the body in weeks to months.
This treatment may cause thyroid activity to slow enough to be considered underactive (hypothyroidism), and you may eventually need to take medication every day to replace thyroxine.
Anti-thyroid medications. These medications gradually reduce symptoms of hyperthyroidism by preventing your thyroid gland from producing excess amounts of hormones. They include methimazole (Tapazole) and propylithiouracil. Symptoms usually begin to improve within several weeks to months, but treatment with anti-thyroid medications typically continues at least a year and often longer.
For some people, this clears up the problem permanently, but other people may experience a relapse. Both drugs can cause serious liver damage, sometimes leading to death. Because propylthiouracil has caused far more cases of liver damage, it generally should be used only when you can't tolerate methimazole.
A small number of people who are allergic to these drugs may develop skin rashes, hives, fever or joint pain. They also can make you more susceptible to infection.
- Beta blockers. Although these drugs are usually used to treat high blood pressure and don't affect thyroid levels, they can ease symptoms of hyperthyroidism, such as a tremor, rapid heart rate and palpitations. For that reason, your doctor may prescribe them to help you feel better until your thyroid levels are closer to normal. These medications generally aren't recommended for people who have asthma, and side effects may include fatigue and sexual dysfunction.
Surgery (thyroidectomy). If you're pregnant or you otherwise can't tolerate anti-thyroid drugs and don't want to or can't have radioactive iodine therapy, you may be a candidate for thyroid surgery, although this is an option in only a few cases.
In a thyroidectomy, your doctor removes most of your thyroid gland. Risks of this surgery include damage to your vocal cords and parathyroid glands — four tiny glands situated on the back of your thyroid gland that help control the level of calcium in your blood.
In addition, you'll need lifelong treatment with levothyroxine (Levoxyl, Synthroid, others) to supply your body with normal amounts of thyroid hormone. If your parathyroid glands also are removed, you'll need medication to keep your blood-calcium levels normal.
If Graves' disease affects your eyes (Graves' ophthalmopathy), you can manage mild signs and symptoms by using artificial tears and lubricating gels and by avoiding wind and bright lights. If your symptoms are more severe, your doctor may recommend treatment with corticosteroids, such as prednisone, to reduce swelling behind your eyeballs.
Two drugs — rituximab (Rituxan) and teprotumumab — are being used to treat Graves' ophthalmopathy, even though there isn't a lot of definitive evidence yet to prove that they're effective. Teprotumumab received fast-track approval from the Food and Drug Administration based on one small study. More study of both drugs as a treatment for Graves' ophthalmopathy is needed.
In some cases, a surgical procedure may be an option:
- Orbital decompression surgery. In this surgery, your doctor removes the bone between your eye socket and your sinuses — the air spaces next to the eye socket. When the procedure is successful, it improves vision and provides room for your eyes to return to their normal position. But there is a risk of complications, including double vision that persists or appears after surgery.
- Eye muscle surgery. Sometimes scar tissue from Graves' ophthalmopathy can cause one or more eye muscles to be too short. This pulls your eyes out of alignment, leading to double vision. Eye muscle surgery may help correct double vision by cutting the affected muscle from the eyeball and reattaching it farther back.
From Mayo Clinic to your inbox
Sign up for free, and stay up to date on research advancements, health tips and current health topics, like COVID-19, plus expertise on managing health.
ErrorEmail field is required
ErrorInclude a valid email address
To provide you with the most relevant and helpful information, and understand which
information is beneficial, we may combine your email and website usage information with
other information we have about you. If you are a Mayo Clinic patient, this could
include protected health information. If we combine this information with your protected
health information, we will treat all of that information as protected health
information and will only use or disclose that information as set forth in our notice of
privacy practices. You may opt-out of email communications at any time by clicking on
the unsubscribe link in the e-mail.
Thank you for subscribing!
You'll soon start receiving the latest Mayo Clinic health information you requested in your inbox.
Sorry something went wrong with your subscription
Please, try again in a couple of minutes
Lifestyle and home remedies
Once you begin treatment, symptoms of hyperthyroidism should subside and you should start feeling much better. However, your doctor may recommend that you watch out for iodine in your diet because it can cause hyperthyroidism or make it worse.
Kelp, dulse and others types of seaweed contain a lot of iodine. Cough syrup and multivitamins also may contain iodine.
If you have Graves' ophthalmopathy or dermopathy, the following suggestions may help your eyes or skin:
- Don't smoke. Smoking has been linked to the development of Graves' ophthalmopathy and can make the condition worse after treatment.
- Keep your eyes lubricated. Eyedrops may help relieve dryness and scratchiness at any time of the day. If your eyes don't completely close, you can tape your eyelids shut, or use a lubricating gel at bedtime to keep the cornea from drying out. A cool compress can also provide relieving moisture.
- Protect your eyes. Wear sunglasses to help protect your eyes from the sun and wind.
- Keep your head up. Raising the head of your bed may reduce swelling and relieve pressure on your eyes.
- Try over-the-counter creams for swollen skin. Over-the-counter creams containing hydrocortisone (Cortizone-10, others) may help relieve red, swollen skin on your shins and feet. For help finding these creams, talk to your pharmacist.
Coping and support
If you've been diagnosed with hyperthyroidism, the most important thing is to receive the necessary medical care. After you and your doctor have decided on a course of action, there are some things you can do that will help you cope with the condition and support your body during its healing process.
- Get regular exercise. Exercise in general will help you feel better and improve your muscle tone and cardiovascular system. Weight-bearing exercise is important for people with Graves' disease because it helps maintain bone density. Exercise also can help reduce your appetite and increase your energy level.
- Learn relaxation techniques. Many relaxation techniques can help you maintain a positive outlook, especially when coping with illness. It is well-documented that in Graves' disease stress is a risk factor, so learning to relax and achieve balance in your life can help maintain physical and mental well-being.
Preparing for your appointment
You'll likely start by seeing your primary care doctor. However, in some cases, you may be referred immediately to a doctor who specializes in the body's hormone-secreting glands (endocrinologist). If you have eye involvement, you may also be referred to an eye doctor (ophthalmologist).
It's good to prepare for your appointment. Here's some information to help you get ready for your appointment, and to know what to expect from your doctor.
What you can do
- Be aware of any pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance.
- Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
- Write down key personal information, including any major stresses or recent life changes.
- Make a list of all medications, vitamins or supplements you're taking, especially any supplements or vitamins containing biotin.
- Take a family member or friend along, if possible. Someone who accompanies you may remember information you missed or forgot.
- Write down questions to ask your doctor.
Preparing a list of questions will help you make the most of your time with your doctor. For hyperthyroidism, some basic questions to ask your doctor include:
- What's the most likely cause of my symptoms?
- Are there other possible causes?
- What tests do I need?
- Is my condition likely temporary or long lasting?
- What treatment options are available, and which do you recommend for me?
- I have these other health conditions. How can I manage these conditions together?
- Should I see a specialist?
- Is there a generic alternative to the medicine you're prescribing?
- Do you have brochures or other printed material I can take? What websites do you recommend?
Don't hesitate to ask any other relevant questions you have.
What to expect from your doctor
Your doctor is likely to ask you a number of questions, including:
- When did you begin having symptoms?
- Have your symptoms been continuous or occasional?
- How severe are your symptoms?
- What, if anything, seems to improve your symptoms?
- What, if anything, makes your symptoms worse?
- Do other members of your family have thyroid disease?
- Have you had any recent radiology scans that used intravenous contrast?
Nov. 14, 2020