Hyperthyroidism (overactive thyroid) is usually managed by a specialist doctor. However, pressures on today’s NHS mean patients can face long waiting times to see an endocrinologist (doctor specialising in hormones).

So, in some cases, your GP may diagnose your condition and start your treatment, under guidance from an endocrinologist, while you wait for a hospital appointment. In this article, we discuss what care you can expect while you wait to see a specialist. We also answer some of your frequently asked questions.

Content overview

What is hyperthyroidism?

Causes of hyperthyroidism

How is hyperthyroidism diagnosed?

How quickly will I be seen by endocrinology?

What treatments can be given in primary care?

How frequently should my thyroid function be monitored?

What dose will I be started on?

Can my GP alter my dose?

Why aren’t all patients given antithyroid drugs during the wait to see endocrinology?

What happens if I have a bad reaction to antithyroid drugs?

How should women with hyperthyroidism be managed in conception and pregnancy?

What happens if they suspect I have thyroid eye disease?

Further information and support 

What is hyperthyroidism?

Hyperthyroidism is an overactivity of the thyroid gland, which means it produces too much thyroid hormone. When the level of thyroid hormones it is too high it is called thyrotoxicosis.

Causes of hyperthyroidism

• Graves’ disease, which is an autoimmune disease. This is the most common cause.
•  A toxic multinodular goitre (an enlarged thyroid gland)
• A solitary toxic adenoma (an adenoma is a clump of cells)
• Certain drugs, including amiodarone, alemtuzumab, immune checkpoint inhibitors and Tyrosine  Kinase Inhibitor (TKI) therapy

Hyperthyroidism in pregnancy (or gestational thyrotoxicosis). This is usually not permanent.

Thyrotoxicosis can also happen without hyperthyroidism.For example, thyroiditis (inflammation or swelling of the thyroid gland) causes a temporary excess of thyroid hormones, but it usually gets  better without treatment.

How is hyperthyroidism diagnosed?

Doctors diagnose an overactive thyroid by physical examination and looking at your blood test results. In hyperthyroidism, your blood tests will usually show high levels of free thyroxine (FT4) and/or free triiodothyronine (FT3) (levels above the reference range). They will also show low Thyroid Stimulating Hormone (TSH) levels below the reference range (usually lower than 0.1 mU/L).

If TSH-receptor antibodies (TRAb) are positive, this confirms a diagnosis of Graves’ disease. Not all  GPs will be able to test for TRAb. Where this is the case, you will need to have these tested for at the hospital. Some hospital laboratories automatically add TRAb to a blood sample if the initial tests reveal thyrotoxicosis. If some hospital laboratories do not offer TRAb tests then they are able to send it a different laboratory to get it tested, if asked by a clinician.

How quickly will I be seen by endocrinology?

Once hyperthyroidism has been confirmed your GP will refer you to an endocrinologist. How quickly you  see them will vary according to where you live. In some cases, it will be weeks, in others it might be months.

• It will also depend upon other factors such as:
•  How high your FT4 and/or FT3 levels are
•  How severe your symptoms are
•  Whether you are pregnant or planning a child
•  Where there are nodules (lumps) and goitres (swellings) that may be causing pressure symptoms  such as breathing or swallowing difficulty)
• If your doctor thinks there may be associated Thyroid Eye Disease (TED).

What treatments can be given in primary care?

Your GP will often prescribe you beta blockers, such as propranolol, straight after diagnosing hyperthyroidism. These can help with symptoms such as palpitations, racing heartbeat, tremor, heat intolerance and anxiety. They should also give you advice on stopping smoking, as this can be a risk factor  for developing TED. It can also make TED symptoms worse.

Once hyperthyroidism caused by Graves’ disease has been confirmed, in some cases, your GP might start you on a course of antithyroid drugs usually under guidance from the local endocrinology team.

Antithyroid drugs aim to reduce the production of thyroid hormones. The antithyroid drug will usually be  carbimazole but propylthiouracil (PTU) may be prescribed during pregnancy, if you are planning a  pregnancy, or if you have had an adverse reaction to carbimazole.

If you have a toxic nodular goitre you will sometimes be given antithyroid drugs to bring your thyroid levels  under control. This is often to prepare you for definitive treatment (designed to provide long-lasting relief) with either radioactive iodine treatment or thyroid surgery.

How frequently should my thyroid function be monitored?

Your healthcare professionals should check your TSH, free thyroxine (FT4) and free triiodothyronine (FT3) every six weeks until the TSH is within the reference range. They will then test your TSH every three months until they stop your antithyroid drugs. If your TSH is abnormal, they should also check your FT4 and FT3.

If you are not started on medication your thyroid function should still be checked at regular intervals or if  symptoms change and there is still a long wait to see the endocrinologist.

What dose will I be started on?

Your dose of antithyroid drugs will depend on various factors, including thyroid hormone levels, age and  whether there are plans for pregnancy etc. The dose usually ranges from 5-40mg daily.

Can my GP alter my dose?

If antithyroid medicine starts to bring your thyroid levels down, your doctor may need to alter your dose  after two to three months. Ideally, your endocrinologist would do this. If you are still waiting to see an  endocrinologist your GP may alter your dose where needed. They will often contact the specialist via the ‘Advice and Guidance’ service before altering your dose.

Why aren’t all patients given antithyroid drugs during the wait to see endocrinology?

If TRAb are confirmed as positive, and if there is a long wait to see an endocrinologist, then most GPs should be able to start you on antithyroid medication after discussing it with the specialist hospital team.

However, if thyroiditis is the likely cause of your thyrotoxicosis (such as after having a baby or after a virus), you will not usually be prescribed antithyroid drugs. This is because the thyrotoxicosis will probably get  better by itself, and taking antithyroid drugs with this condition can mean your recovery takes longer.

What happens if I have a bad reaction to antithyroid drugs?

Antithyroid drugs can cause minor side effects, such as altered taste sensation or nausea. This is usually in  the first few weeks. Some people develop an itchy, red rash. This will normally clear up with antihistamine  medications or once the drug is stopped. If this happens, your doctor may consider switching you over to a  different antithyroid drug. Very occasionally carbimazole and PTU cause the white blood cells that help to  fight infection to drop. This may be a serious and life-threatening condition called agranulocytosis.

If you develop a sore throat, mouth ulcers or unexplained fever, you should stop taking your tablets  immediately and go to your GP or A&E department and ask for a full blood count.

If you are taking PTU, there is a small risk of serious liver injury. If you notice your eyes or skin becoming  yellow, or experience nausea (feeling sick) or loss of appetite, you should contact your doctor immediately. Your doctor should discuss these rare side effects with you before starting antithyroid drugs.

How should women with hyperthyroidism be managed in conception and pregnancy?

If you are pregnant or are trying to have a baby, and you have hyperthyroidism, subclinical (or borderline)  hyperthyroidism, or a history of hyperthyroidism, your doctor should urgently refer you to a joint obstetric  (dealing with pregnant women and women giving birth) and endocrinology clinic, if there is one in your  area. In other areas, your doctor may refer you to an obstetric or endocrinology unit.

This is because uncontrolled, or untreated, hyperthyroidism can make it difficult to get pregnant. It can also lead to complications in pregnancy. If you are planning pregnancy, you should ideally wait until your thyroid levels have returned to normal. If you are taking antithyroid drugs when you become pregnant, your doctor may switch you to PTU. This drug is safer in pregnancy.

What happens if they suspect I have thyroid eye disease?

Dry eyes, excessive tearing and grittiness are relatively common in Graves’ disease. The endocrinology team
should normally check your eyes for any signs of TED. They may refer you to an ophthalmologist (eye doctor) or joint thyroid eye clinic, if needed.

If you start to experience problems like blurred or double vision while waiting to see an endocrinologist, you must tell your GP. They will refer you to a specialist eye doctor (ophthalmologist). Your high street  optician may also be able to refer you where appropriate.

This article was first published in our member magazine, 'BTF News', in April 2025. To receive our magazine, regular updates and other benefits, please consider becoming a BTF member.

Further information and support 

Living with hyperthyroidism

Living with thyroid eye disease

Thyroid disease and pregnancy

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