Graves' disease is an autoimmune disease in which the immune system makes antibodies that switch on the thyroid gland. These antibodies, called TSH-receptor antibodies (TRAb or TSI), keep the gland in overdrive, so it makes too much thyroid hormone. The result is hyperthyroidism, or an overactive thyroid: a racing heart, weight loss, shaky hands, sweating and feeling hot. Some people also develop bulging, gritty or red eyes.
Graves' disease is the most common cause of hyperthyroidism. It affects nearly 1 in 100 Americans and explains about 4 out of 5 cases of overactive thyroid in the United States, according to the NIDDK. It is diagnosed with blood tests (low TSH, high free T4 or T3, positive TSH-receptor antibodies) and is very treatable with tablets, radioactive iodine or surgery.
This guide explains how to read your thyroid results, how Graves' disease differs from other causes of hyperthyroidism, how each treatment works and what changed between 2023 and 2026.
Key takeaways
- Graves' disease is caused by antibodies that stimulate the TSH receptor of the thyroid. It is far more common in women and usually starts between 30 and 60.
- The typical blood pattern is a very low TSH with a high free T4 and/or T3. A positive TRAb test confirms Graves' disease in most people.
- Other causes of hyperthyroidism need different care: toxic nodules, thyroiditis and an excessive dose of levothyroxine.
- Methimazole is the usual first treatment for 12 to 18 months; radioactive iodine and surgery are permanent options. Fever or sore throat on these drugs needs an urgent blood count.
- Smoking makes Graves' eye disease worse. New drugs (teprotumumab, veligrotug) now treat moderate-to-severe thyroid eye disease.
What is Graves' disease?
The thyroid is a butterfly-shaped gland in the neck. The pituitary gland sends thyroid-stimulating hormone (TSH) to tell it how much thyroxine (T4) and triiodothyronine (T3) to make; these hormones set the speed of your metabolism, heart rate and body temperature.
In Graves' disease, the immune system makes autoantibodies that look like TSH to the thyroid. They act as an accelerator that never lifts: the gland grows (a smooth goiter) and escapes the control of the pituitary. With the IGF-1 receptor, the same antibodies also drive the eye and skin changes (Nature Reviews Disease Primers, 2020).
To understand the hormone that falls when the thyroid is overactive, see our guide to the TSH blood test.
Hyperthyroidism vs thyrotoxicosis
Doctors use two words. Thyrotoxicosis means there is too much thyroid hormone in the blood, whatever the reason. Hyperthyroidism means the thyroid itself is making too much. The difference matters: in thyroiditis the gland leaks stored hormone without making more, so drugs that block hormone production do not help.
Causes of hyperthyroidism and risk factors
Graves' disease is the main cause, but not the only one. The NIDDK and the American Thyroid Association list:
- Graves' disease: autoimmune, the most common cause.
- Toxic nodules (toxic adenoma or toxic multinodular goiter): one or several lumps that work on their own. They are more common in older adults. If you have a lump, our article on the thyroid nodule blood test explains what TSH tells you.
- Thyroiditis: inflammation after a virus (subacute), after pregnancy (postpartum) or from some medicines. It usually settles in weeks to months.
- Too much thyroid hormone medicine: an excessive dose of levothyroxine, often in people treated for an underactive thyroid.
- Too much iodine: kelp and other seaweed, iodine supplements, iodine contrast dye or amiodarone.
- Rarely, a noncancerous pituitary tumour that makes TSH.
For Graves' disease itself, the European Thyroid Association (ETA) estimates that about 3% of women and 0.5% of men develop it during their lifetime, with a peak between ages 30 and 60. Risk factors are being a woman, a family history of Graves' or Hashimoto's disease, smoking, high iodine intake, stress, a recent pregnancy and another autoimmune disease such as type 1 diabetes, vitiligo or rheumatoid arthritis (see our overview of autoimmune disease symptoms).
Graves' disease symptoms and warning signs
Excess thyroid hormone speeds up almost every organ. Common symptoms are:
- Fast or irregular heartbeat, palpitations.
- Weight loss despite a normal or bigger appetite. If you are losing weight without trying, see what blood tests show in unexplained weight loss.
- Shaky hands (tremor), muscle weakness, especially climbing stairs.
- Sweating, feeling hot, trouble tolerating heat.
- Frequent bowel movements, lighter periods, thinning hair, poor sleep, fatigue and a swollen neck (goiter).
Emotional symptoms of Graves' disease
Nervousness, irritability, restlessness, mood swings and poor concentration are common and can be mistaken for an anxiety disorder. They usually improve as hormone levels return to normal. Our page on anxiety symptoms and causes can help you compare.
Symptoms in women and in older adults
Graves' disease symptoms in women often include menstrual changes and fertility problems. In older adults, the picture can be quiet: fatigue, low mood, breathlessness or withdrawal (apathetic thyrotoxicosis), sometimes mistaken for depression or dementia.
Graves' eye disease and skin changes
Graves' eye disease, also called thyroid eye disease (TED) or Graves' orbitopathy, affects more than 1 in 3 people with Graves' disease (up to 40% in the 2022 ATA/ETA consensus). The tissues and muscles behind the eye swell. Signs include:
- Gritty, dry or watering eyes, redness, sensitivity to light.
- Puffy eyelids, bulging eyes (proptosis), double vision or pain when moving the eyes.
- Rarely, blurred or dimmer colours: a sign of pressure on the optic nerve and an emergency.
Most cases are mild. Eye disease can occur even with normal thyroid levels. Smoking, poorly controlled thyroid levels and radioactive iodine are the main modifiable risk factors.
Skin changes are rarer. Graves' dermopathy (pretibial myxooedema) causes thick, reddish, rough skin, usually on the shins.
Diagnosis: TSH, T4, T3 and TRAb tests
Symptoms alone cannot confirm hyperthyroidism, so your doctor combines an exam with tests:
- TSH: the best single screening test. It is low or undetectable in hyperthyroidism.
- Free T4: the main hormone. It is high in overt hyperthyroidism. Our guide to the free T4 blood test explains each result.
- Free or total T3: often rises more than T4 in Graves' disease and toxic nodules. Read more about the T3 blood test.
- TRAb or TSI (TSH-receptor antibodies): the test for Graves' disease. In the ETA guideline, modern assays have a pooled sensitivity of 97% and a specificity of 98%.
- Thyroid peroxidase antibodies: often positive in Graves' and Hashimoto's disease, but they do not prove which one you have. See our guide to anti-TPO antibodies.
- Radioactive iodine uptake (RAIU) and scan: high, even uptake points to Graves' disease, hot spots to nodules, low uptake to thyroiditis or excess hormone. Not done in pregnancy.
- Thyroid ultrasound with Doppler: shows a very vascular gland in Graves' disease. If your report mentions a mottled texture, see our article on heterogeneous thyroid echotexture.
Reference values and typical patterns
Ranges vary between laboratories, so compare with the range on your report. Adult ranges below come from MedlinePlus (SI units, as used in the UK, before US units).
| Test | Usual adult range (SI / US) | Typical in Graves' hyperthyroidism |
|---|---|---|
| TSH | About 0.4 to 4.8 mIU/L (same as µU/mL) | Below 0.1 mIU/L, often undetectable |
| Free T4 | 10.3 to 24.5 pmol/L (0.8 to 1.9 ng/dL) | Above the upper limit; normal in T3 toxicosis and subclinical disease |
| Total T3 | 1.2 to 2.4 nmol/L (78 to 158 ng/dL) | High, often proportionally more than T4 |
| Free T3 | Laboratory-specific (pg/mL or pmol/L) | High |
| TRAb / TSI | Below the laboratory cut-off | Positive in most people with Graves' disease |
| Radioactive iodine uptake | 5% to 15% at 6 hours; 10% to 30% at 24 hours | High and diffuse (low in thyroiditis or excess hormone pills) |
Here is how the main patterns read:
| Pattern | TSH | Free T4 / T3 | Likely meaning |
|---|---|---|---|
| Overt hyperthyroidism | Low | Both high | Graves', toxic nodules, thyroiditis or excess hormone; TRAb and uptake sort them out |
| T3 toxicosis | Low | T4 normal, T3 high | Early Graves' disease or a toxic nodule |
| Subclinical hyperthyroidism | Low | Both normal | Mild disease, levothyroxine excess, recovery phase; recheck |
| Possible assay interference | Low | High, but you feel well | Biotin supplements; repeat after stopping them |
For a full view of normal ranges by age and pregnancy, see normal thyroid levels explained.
Other blood findings in hyperthyroidism
- Liver tests: a 2021 meta-analysis found at least one abnormal liver test in 60% of people with untreated Graves' disease. Alkaline phosphatase was raised in 44% of hyperthyroid patients. See our guide to the alkaline phosphatase (ALP) test.
- Cholesterol: hyperthyroidism lowers cholesterol. After treatment of overt disease, total cholesterol rose by about 1.15 mmol/L (44.5 mg/dL) and LDL by about 0.80 mmol/L (31.1 mg/dL) in a 2020 meta-analysis. Our page on the total cholesterol test explains the numbers.
- Blood count: on antithyroid drugs, a rare reaction can wipe out neutrophils. Our guide to low absolute neutrophils explains the thresholds.
How to read your results
A low TSH alone is not a diagnosis. Our article on a low TSH level lists the many causes, from a recent illness to steroid medicines. A few practical points:
- Subclinical hyperthyroidism (low TSH, normal T4 and T3) is often watched. The ETA advises treatment after age 65 when TSH stays below 0.1 mIU/L, and considering it at 0.1 to 0.39 mIU/L because of the risk of atrial fibrillation and fractures.
- A negative TRAb does not always exclude mild Graves' disease: a 2026 study found that, in subclinical cases, assays detected it in only 43% to 71% of patients.
- Biotin (vitamin B7), even at 5 to 20 mg a day in hair and nail supplements, can make T4 and T3 look high and TSH look low. Stopping it for 24 to 72 hours before the test is usually enough for over-the-counter doses; tell your lab.
Treatment options for Graves' disease
There are three ways to control the thyroid, plus medicine for symptoms. The choice depends on your age, goiter size, eye disease, pregnancy plans and preference.
Beta-blockers for fast relief
Propranolol or atenolol slow the heart and calm tremor and anxiety within hours. They do not lower hormone levels and are used until the other treatments work.
Antithyroid drugs: methimazole and PTU
Methimazole blocks thyroid peroxidase, the enzyme that makes thyroid hormone (ChEMBL). In the UK, carbimazole is usually prescribed first; the body converts it to methimazole, so the two work in the same way. Either is the first choice for most adults: usually 10 to 30 mg once a day at the start, then 2.5 to 10 mg, for 12 to 18 months. About 50% to 55% of people are in remission when it is stopped; relapse is more likely with a large goiter, high TRAb, eye disease or smoking. Propylthiouracil (PTU) is reserved mainly for the first trimester of pregnancy and thyroid storm, because it carries a boxed warning for severe liver injury.
Two rare side effects need immediate action:
- Agranulocytosis, a collapse of neutrophils, in 0.1% to 1% of people. If you get fever, sore throat or mouth ulcers, stop the tablets and get a complete blood count the same day.
- Liver injury: jaundice, dark urine, pale stools or itching need an urgent liver test. Our guide to liver function tests explains the results.
Long-term methimazole
Treatment no longer has to stop at 18 months. In a meta-analysis of treatment lasting more than 24 months, remission reached 57%, with major complications in 1.5%. The ETA lists long-term low-dose methimazole as an option for people who relapse and prefer to avoid a permanent treatment.
Radioactive iodine (I-131)
A capsule or liquid of radioactive iodine is taken up by the thyroid and slowly destroys the overactive cells over weeks to months. About 10% of people need a second dose. Almost everyone becomes hypothyroid afterwards and takes levothyroxine for life, which is easy to manage. It is not used in pregnancy or breastfeeding, and it can worsen eye disease, especially in smokers; steroid cover may be offered. Our guide to hypothyroidism explains life after treatment.
Thyroid surgery
Total thyroidectomy removes the gland and cures the hyperthyroidism. It is chosen for large goiters or in pregnancy when drugs fail. Risks include low calcium and a hoarse voice, so an experienced high-volume surgeon matters.
Follow-up
Hormone levels can take weeks or months to normalise, so tests are frequent at first. After stopping methimazole, check them closely for a year, then at least yearly; after radioactive iodine, every 1 to 3 months until stable.
Thyroid storm: a rare emergency
Thyroid storm is an extreme, life-threatening flare of untreated or poorly controlled hyperthyroidism. It is usually triggered by a major stress such as an infection, an injury, surgery or a heart attack, and rarely by radioactive iodine treatment. Signs include high fever, a very fast heartbeat, agitation or confusion, vomiting, diarrhoea, jaundice and heart failure. In Japanese national surveys it occurred in 0.22% of thyrotoxic patients and 10.7% died. Treatment combines antithyroid drugs, steroids and a beta-blocker, with monitoring in intensive care.
Diet, lifestyle and prevention
You cannot fully prevent Graves' disease, but you can help treatment work:
- Stop smoking: it raises the risk of the disease, lowers remission rates and worsens eye disease. Free help: the NHS Smokefree helpline, 0300 123 1044.
- Avoid large amounts of iodine: kelp, dulse, other seaweed and iodine supplements. Check cough syrups and multivitamins.
- Selenium: for mild, active eye disease, the ATA/ETA consensus suggests selenium selenite 100 µg twice daily for 6 months, especially where selenium intake is low. It does not treat the hyperthyroidism itself. See our page on the selenium blood test.
- Diet and exercise: eat enough protein, calcium and vitamin D for muscles and bones, limit caffeine and keep exercise light until your heart rate is controlled.
- Protect your eyes: sunglasses and lubricating eye drops help mild symptoms.
Pregnancy, children and older adults
Pregnancy
Ideally, thyroid levels are stable before conceiving. The ETA and the 2017 ATA pregnancy guideline advise switching from methimazole to PTU when planning pregnancy and during the first trimester, because methimazole is linked to more birth defects than PTU. Thyroid tests are checked every 4 weeks. TRAb is measured, because these antibodies cross the placenta: levels more than 3 times the cut-off late in pregnancy call for monitoring of the baby for neonatal hyperthyroidism. Many women can stop treatment in the third trimester. Methimazole is preferred while breastfeeding. Our guide to blood tests during pregnancy covers the routine checks.
Children and teens
Graves' disease can also start in childhood. Methimazole is used for 24 to 36 months; PTU is avoided in children because of liver risk.
Older adults
After 60, toxic nodules and too much levothyroxine become frequent causes. Excess thyroid hormone raises the risk of atrial fibrillation, heart failure and osteoporosis. A 2026 review notes that excessive levothyroxine is the most common cause of subclinical hyperthyroidism at this age.
When to see a doctor
See your doctor if you have palpitations, unexplained weight loss, tremor, heat intolerance, a swollen neck, or gritty, red or bulging eyes.
Call 999 or go to A&E if you have:
- High fever with a racing heart, confusion or agitation (possible thyroid storm).
- Chest pain, fainting, severe shortness of breath or a very fast irregular pulse (possible atrial fibrillation).
- Sudden loss of vision, dim colours or severe eye pain.
If you take methimazole or PTU, call your doctor the same day for fever, sore throat, mouth ulcers or yellow skin.
Latest scientific advances in Graves' disease
IGF-1 receptor antibodies for thyroid eye disease
Teprotumumab (Tepezza), an IGF-1 receptor blocker approved in 2020, is given as 8 infusions every 3 weeks. A 2023 trial showed it also reduces bulging in long-standing, low-activity eye disease (2.41 mm vs 0.92 mm with placebo), with hearing problems in 22% vs 10%. The 2022 ATA/ETA consensus places it first for most moderate-to-severe active eye disease; the 2021 EUGOGO guideline starts with intravenous steroids. For you: if your eyes bulge or you see double, ask about these options, and report any hearing change during treatment.
Veligrotug: a shorter course
In the THRIVE phase 3 trial published in 2026, veligrotug, a full IGF-1 receptor antagonist, was given in only 5 infusions over 12 weeks to 113 patients. Proptosis improved in 70% vs 5% with placebo, double vision resolved in 49% vs 12%, and 70% of responders kept their response at week 52. A 2026 US analysis describes it as recently approved, at about 450,000 dollars per course.
FcRn blockers that lower the antibodies
FcRn blockers make the body break down its IgG antibodies faster, including TRAb. In a phase 2 study of batoclimab (NCT05907668), thyroid levels normalised quickly in people not controlled by tablets; one patient remained in remission 23 months after stopping. Phase 2b trials of IMVT-1402 (NCT06727604) and phase 3 trials of efgartigimod (NCT07570316) in Graves' disease are under way; efgartigimod trials in eye disease were stopped early, so results are awaited.
Oral and targeted options in the pipeline
Linsitinib, a tablet that blocks the IGF-1 receptor, reduced proptosis in a phase 2b/3 study (NCT05276063) and entered a phase 3 trial in 2026 (NCT07753603). TSH-receptor blocking antibodies (K1-70) and antigen-specific immunotherapy are in earlier trials, aiming to switch off the autoimmune cause rather than the gland.
Which tests can help?
A thyroid panel with TSH, free T4 and T3 is the starting point; TRAb or TSI confirms Graves' disease, and an uptake scan or ultrasound settles doubtful cases. During treatment, a complete blood count and liver tests are checked when symptoms appear, and glucose, calcium and lipids complete the picture. Our guide to the complete blood count explains what your white cells, red cells and platelets show.
Glossary
- TSH: thyroid-stimulating hormone, made by the pituitary; low in hyperthyroidism.
- Free T4 and T3: the active thyroid hormones not bound to proteins.
- TRAb / TSI: TSH-receptor antibodies; thyroid-stimulating immunoglobulins are the stimulating type.
- Thyrotoxicosis: too much thyroid hormone in the blood, whatever the cause.
- Pretibial myxooedema: thick, reddish skin on the shins in Graves' disease.
- Agranulocytosis: a severe fall in neutrophils, a rare side effect of antithyroid drugs.
- Thyroid storm: a life-threatening surge of thyroid hormone effects.
Frequently asked questions
What are the treatment options for Graves' disease?
Beta-blockers for symptoms, then methimazole tablets (often 12 to 18 months, sometimes longer), radioactive iodine or thyroid surgery. Eye disease may need selenium, steroids, teprotumumab or eye surgery.
Is Graves' disease curable?
About half of people stay in remission after a course of methimazole. Radioactive iodine and surgery end the hyperthyroidism for good, but you then need lifelong levothyroxine.
What are the emotional symptoms associated with Graves' disease?
Anxiety, irritability, mood swings, restlessness, poor concentration and insomnia. They usually ease as hormone levels normalise; talk to your doctor if they persist.
What are the recommended diet and exercise for people with Graves' disease?
No special diet cures it. Avoid iodine-rich seaweed and supplements, eat enough calories, protein, calcium and vitamin D, limit caffeine and keep exercise gentle until your heart rate is controlled.
What is the test for Graves' disease?
A blood test for TSH, free T4 and T3, plus TSH-receptor antibodies (TRAb or TSI). An uptake scan or Doppler ultrasound helps when results are unclear.
What is the difference between Graves' disease and hyperthyroidism?
Hyperthyroidism is the state of an overactive thyroid. Graves' disease is one cause of it, the most common one; toxic nodules, thyroiditis and excess medicine are others.
Sources
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- Kahaly GJ et al. — 2018 European Thyroid Association Guideline for the Management of Graves' Hyperthyroidism — Eur Thyroid J, 2018 — doi.org
- Burch HB et al. — Management of Thyroid Eye Disease: ATA/ETA Consensus Statement — Thyroid, 2022 — doi.org
- Bartalena L et al. — EUGOGO 2021 guidelines vs 2022 ATA/ETA consensus on Graves' orbitopathy — Eur Thyroid J, 2025 — doi.org
- Alexander EK et al. — 2017 ATA Guidelines for Thyroid Disease During Pregnancy and the Postpartum — Thyroid, 2017 — doi.org
- Davies TF et al. — Graves' disease — Nat Rev Dis Primers, 2020 — doi.org
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- Douglas RS et al. — Teprotumumab in long-duration, low-activity thyroid eye disease — J Clin Endocrinol Metab, 2023 — doi.org
- Yen MT et al. — THRIVE: phase 3 trial of veligrotug for active thyroid eye disease — Ophthalmology, 2026 — doi.org
- Li Z et al. — Cost-effectiveness of veligrotug vs teprotumumab in the United States — Expert Rev Pharmacoecon Outcomes Res, 2026 — doi.org
- Middleton F, Abraham P — New horizons for autoimmune hyperthyroidism with FcRn blockers — Curr Opin Endocrinol Diabetes Obes, 2026 — doi.org
- Lee ACH, Kahaly GJ — Targeted immunotherapies for Graves' thyroidal and orbital diseases — Front Immunol, 2025 — doi.org
- Immunovant — Batoclimab in Graves' disease (NCT05907668) — ClinicalTrials.gov, 2023-2025 — clinicaltrials.gov
- Sling Therapeutics — Linsitinib in thyroid eye disease (NCT05276063) — ClinicalTrials.gov, 2022-2026 — clinicaltrials.gov
- U.S. Food and Drug Administration — Tepezza (teprotumumab-trbw) prescribing information — FDA, 2020 — accessdata.fda.gov
- NIDDK — Graves' Disease — NIH, 2021 — niddk.nih.gov
- NIDDK — Hyperthyroidism (Overactive Thyroid) — NIH, 2021 — niddk.nih.gov
- American Thyroid Association — Hyperthyroidism (Overactive) — ATA patient information — thyroid.org
- MedlinePlus — Free T4 test; T3 test; TSH test; Radioactive iodine uptake; Thyroid storm; Graves disease — NLM, 2025 — medlineplus.gov
- ChEMBL — Methimazole (CHEMBL1515), propylthiouracil (CHEMBL1518), teprotumumab (CHEMBL1743079) — EMBL-EBI — ebi.ac.uk
- NHS — Overactive thyroid (hyperthyroidism) — NHS, nhs.uk — nhs.uk
Further reading
- Low TSH level: meaning, causes and symptoms
- TSH blood test: how to read your results
- Free T4 blood test: how to read your result
- T3 blood test: what high and low levels mean
- Hypothyroidism: symptoms, causes and treatment
- Normal thyroid levels: how to read your results
- Anti-TPO antibodies: meaning, levels and causes
- Thyroid cancer: symptoms, types and outlook
Understand your lab results with AI DiagMe
With Graves' disease, every visit comes with a new set of numbers: TSH, free T4, T3, antibodies, blood count and liver tests. AI DiagMe reads your lab report in minutes and explains each value in plain language, shows how your results compare with the reference ranges, and suggests questions to ask your doctor. Upload your thyroid test results to AI DiagMe for a clear, personal report.
