Thyroid disease: assessment and management

Ensure that information is presented to facilitate shared decision making, as recommended in the NICE guideline on shared decision making.

Explain to people with thyroid disease who need treatment, and their family or carers if appropriate, that:

• Thyroid disease usually responds well to treatment.

• The goal of treatment is to alleviate symptoms and align thyroid function tests within or close to the reference range.

• People may feel well even when their thyroid function tests are outside the reference range.

• Even when there are no symptoms, treatment may be advised to reduce the risk of long-term complications.

• Even when thyroid function tests are within the reference range, changes to treatment may improve symptoms for some people.

• Symptoms may lag behind treatment changes for several weeks to months.

• Day-to-day changes in unexplained symptoms are unlikely to be due to underlying thyroid disease because the body has a large reservoir of thyroxine.

Provide people with thyroid disease, and their family or carers if appropriate, with written and verbal information on:

• their underlying condition, including the role and function of the thyroid gland and what the thyroid function tests mean

• risks of over- and under-treatment

• their medicines

• need for and frequency of monitoring

• when to seek advice from a healthcare professional

• how thyroid disease and medicines may affect pregnancy and fertility.

Provide people with hypothyroidism, and their family or carers if appropriate, with written and verbal information on:

• possible drug interactions of thyroid hormone replacements, including interactions with over-the-counter medicines

• how and when to take levothyroxine.

Provide people with thyrotoxicosis, and their family or carers if appropriate, with written and verbal information on:

• the different causes of thyrotoxicosis

• the consequences of untreated thyrotoxicosis

• the suitability of individual treatment options (for example, antithyroid drugs may be more suitable for mild uncomplicated Graves' disease, surgery may be best for an enlarged thyroid causing compression, radioactive iodine is not usually suitable before puberty)

• the possible benefits/advantages of the treatment options (for example, antithyroid drugs and radioactive iodine are non-invasive treatments, surgery offers rapid relief of symptoms and there is no need to delay pregnancy or fathering a child)

• the possible risks/disadvantages of the treatment options (for example, antithyroid drugs may have side effects, radioactive iodine means limited contact with other people for a few weeks and a need to delay pregnancy or fathering a child, surgery is an invasive treatment that leaves scarring on the neck)

• the risk of and impact of different treatment options on new and existing thyroid eye disease (for example, radioactive iodine may precipitate or worsen thyroid eye disease)

• the need for thyroid hormone replacement if treatment leads to life-long hypothyroidism.

Provide people with thyroid enlargement, and their family or carers if appropriate, with written and verbal information on:

• the causes of thyroid enlargement, including the fact that goitre and nodules are common and are usually not cancerous

• red flag symptoms to look out for (for example, shortness of breath, rapid growth of nodules, hoarse voice, swallowing difficulties)

• treatment options.

Consider tests for thyroid dysfunction for adults, children and young people if there is a clinical suspicion of thyroid disease, but bear in mind that 1 symptom alone may not be indicative of thyroid disease.

Offer tests for thyroid dysfunction to adults, children and young people with:

• type 1 diabetes or other autoimmune diseases, or

• new-onset atrial fibrillation.

Consider tests for thyroid dysfunction for adults, children and young people with depression or unexplained anxiety.

Consider tests for thyroid dysfunction for children and young people with abnormal growth, or unexplained change in behaviour or school performance.

Be aware that in menopausal women symptoms of thyroid dysfunction may be mistaken for menopause.

Do not test for thyroid dysfunction during an acute illness unless you suspect the acute illness is due to thyroid dysfunction, because the acute illness may affect the test results.

Do not offer testing for thyroid dysfunction solely because an adult, child or young person has type 2 diabetes.

Consider measuring thyroid-stimulating hormone (TSH) alone for adults when secondary thyroid dysfunction (pituitary disease) is not suspected. Then:

• if the TSH is above the reference range, measure free thyroxine (FT4) in the same sample

• if the TSH is below the reference range, measure FT4 and free tri-iodothyronine (FT3) in the same sample.

Consider measuring both TSH and FT4 for:

• adults when secondary thyroid dysfunction (pituitary disease) is suspected

• children and young people.
  
  If the TSH is below the reference range, measure FT3 in the same sample.

Consider repeating the tests for thyroid dysfunction in recommendations 1.2.8 or 1.2.9 if symptoms worsen or new symptoms develop (but no sooner than 6 weeks from the most recent test).

Ask adults, children and young people with suspected thyroid dysfunction about their biotin intake because a high consumption of biotin from dietary supplements may lead to falsely high or low test results. [2023]

Offer levothyroxine as first-line treatment for adults, children and young people with primary hypothyroidism.

Do not routinely offer liothyronine for primary hypothyroidism, either alone or in combination with levothyroxine, because there is not enough evidence that it offers benefits over levothyroxine monotherapy, and its long-term adverse effects are uncertain.

Do not offer natural thyroid extract for primary hypothyroidism because there is not enough evidence that it offers benefits over levothyroxine, and its long-term adverse effects are uncertain.

Natural thyroid extract does not have a UK marketing authorisation so its safety is uncertain.

Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

Consider starting levothyroxine at a dosage of 25 to 50 micrograms per day with titration for adults aged 65 and over and adults with a history of cardiovascular disease.

Aim to maintain TSH levels within the reference range when treating primary hypothyroidism with levothyroxine. If symptoms persist, consider adjusting the dose of levothyroxine further to achieve optimal wellbeing, but avoid using doses that cause TSH suppression or thyrotoxicosis.

Be aware that the TSH level can take up to 6 months to return to the reference range for people who had a very high TSH level before starting treatment with levothyroxine or a prolonged period of untreated hypothyroidism. Take this into account when adjusting the dose of levothyroxine.

When discussing whether or not to start treatment for subclinical hypothyroidism, take into account features that might suggest underlying thyroid disease, such as symptoms of hypothyroidism, previous radioactive iodine treatment or thyroid surgery, or raised levels of thyroid autoantibodies.

Be aware that transient thyrotoxicosis without hyperthyroidism usually only needs supportive treatment (for example, beta-blockers).

Consider antithyroid drugs along with supportive treatment for adults with hyperthyroidism who are waiting for specialist assessment and further treatment.

Use of carbimazole is subject to MHRA advice on contraception (Drug Safety Update, February 2019) and risk of acute pancreatitis (Drug Safety Update, February 2019).

Discuss with adults, children and young people with thyrotoxicosis with hyperthyroidism (and their families and carers as appropriate):

• the possible benefits and risks of all treatment options (antithyroid drugs, radioactive iodine, surgery)

• the likelihood of a good response to each option.

Ensure that people can actively participate in decisions about their treatment by following the recommendations in the NICE guidelines on patient experience in adult NHS services and shared decision making. This includes presenting information about possible outcomes in a way the person (and their families and carers as appropriate) can understand.

Offer antithyroid drugs to control hyperthyroidism in adults, children and young people who are waiting for treatment with radioactive iodine or surgery.

Use of carbimazole is subject to MHRA advice on contraception (Drug Safety Update, February 2019) and risk of acute pancreatitis (Drug Safety Update, February 2019). November 2019 – carbimazole use is off label for children under 2 years. See NICE's information on prescribing medicines.

Before starting antithyroid drugs for adults, children and young people with hyperthyroidism, check full blood count and liver function tests.

When offering antithyroid drugs as first-line definitive treatment to adults with Graves' disease, offer carbimazole for 12 to 18 months, using either a block and replace or a titration regimen, and then review the need for further treatment.

Use of carbimazole is subject to MHRA advice on contraception (Drug Safety Update, February 2019) and risk of acute pancreatitis (Drug Safety Update, February 2019).

When offering antithyroid drugs to children and young people with Graves' disease, offer carbimazole, using a titration regimen, and review the need for treatment every 2 years.

Use of carbimazole is subject to MHRA advice on contraception (Drug Safety Update, February 2019) and risk of acute pancreatitis (Drug Safety Update, February 2019). November 2019 – carbimazole use is off label for children under 2 years. See NICE's information on prescribing medicines.

When offering life-long antithyroid drugs to adults with hyperthyroidism secondary to a single or multiple toxic nodules, consider treatment with a titration regimen of carbimazole.

Consider propylthiouracil for adults:

• who experience adverse reactions to carbimazole

• who are pregnant or trying to become pregnant within the following 6 months

• with a history of pancreatitis.

Stop and do not restart any antithyroid drugs if a person develops agranulocytosis. Consider referral to a specialist for further management options.

Consider measuring TSH, FT4 and FT3 levels in adults, children and young people every 6 weeks for the first 6 months after radioactive iodine treatment until TSH is within the reference range.

For adults, children and young people who have hypothyroidism after radioactive iodine treatment and are not on antithyroid drugs, offer levothyroxine replacement therapy and follow recommendations 1.3.6 and 1.3.7 on dosage of levothyroxine for adults and 1.4.1 to 1.4.6 on monitoring of hypothyroidism.

For adults, children and young people with TSH in the reference range 6 months after radioactive iodine treatment, consider measuring TSH (with cascading) at 9 months and 12 months after treatment.

For adults, children and young people with TSH in the reference range 12 months after radioactive iodine treatment, consider measuring TSH (with cascading) every 6 months unless they develop hypothyroidism (then follow recommendation 1.7.2).

If hyperthyroidism persists after radioactive iodine treatment in adults, children and young people, consider antithyroid drugs until the 6-month appointment.

Use of carbimazole is subject to MHRA advice on contraception (Drug Safety Update, February 2019) and risk of acute pancreatitis (Drug Safety Update, February 2019). November 2019 – carbimazole use is off label for children under 2 years. See NICE's information on prescribing medicines.

If hyperthyroidism persists 6 months after radioactive iodine treatment in adults, children and young people, consider further treatment.

Offer levothyroxine to adults, children and young people after a total thyroidectomy and follow recommendations 1.3.6 and 1.3.7 on dosage of levothyroxine for adults and 1.4.1 to 1.4.6 on monitoring of hypothyroidism.

Consider measuring TSH and FT4 at 2 and 6 months after surgery, and then TSH (with cascading) once a year for adults, children and young people who have had a hemithyroidectomy.

For adults, children and young people who are taking antithyroid drugs for hyperthyroidism, consider measuring:

• TSH, FT4 and FT3 every 6 weeks until their TSH is within the reference range, then

• TSH (with cascading) every 3 months until antithyroid drugs are stopped.

Do not monitor full blood count and liver function for adults, children and young people taking antithyroid drugs for hyperthyroidism unless there is a clinical suspicion of agranulocytosis or liver dysfunction.

For adults who have stopped antithyroid drugs, consider measuring:

• TSH (with cascading) within 8 weeks of stopping the drug, then

• TSH (with cascading) every 3 months for a year, then

• TSH (with cascading) once a year.

For children and young people who have stopped antithyroid drugs, consider measuring:

• TSH, FT4 and FT3 within 8 weeks of stopping the drug, then

• TSH, FT4 and FT3 every 3 months for the first year, then

• TSH (with cascading) every 6 months for the second year, then

• TSH (with cascading) once a year.

Consider seeking specialist advice on managing subclinical hyperthyroidism in adults if they have:

• 2 TSH readings lower than 0.1 Miu/litre at least 3 months apart and

• evidence of thyroid disease (for example, a goitre or positive thyroid antibodies) or symptoms of thyrotoxicosis.

Consider seeking specialist advice on managing subclinical hyperthyroidism in all children and young people.

Consider measuring TSH every 6 months for adults with untreated subclinical hyperthyroidism. If the TSH level is outside the reference range, consider measuring FT4 and FT3 in the same sample.

Consider measuring TSH, FT4 and FT3 every 3 months for children and young people with untreated subclinical hyperthyroidism.

Consider stopping TSH measurement for adults, children and young people with untreated subclinical hyperthyroidism if the TSH level stabilises (2 similar measurements within the reference range 3 to 6 months apart).

Offer ultrasound to image palpable thyroid enlargement or focal nodularity in adults, children and young people with normal thyroid function if malignancy is suspected.

Consider ultrasound of incidental findings on imaging if clinical factors suggest malignancy as a possibility.

When making decisions about whether to offer fine needle aspiration cytology, use an established system for grading ultrasound appearance that takes into account:

• echogenicity

• microcalcifications

• border

• shape in transverse plane

• internal vascularity

• lymphadenopathy.

Reports of ultrasound findings should:

• specify which grading system has been used for the assessment.

• include information on the features in recommendation 1.9.3 and

• provide an overall assessment of malignancy, and

• confirm that both lobes have been assessed, and

• document assessment of cervical lymph nodes.

Use ultrasound guidance when performing fine needle aspiration cytology.

See the NICE guideline on suspected cancer for recommendations on referral for suspected head and neck cancers (including thyroid cancer).

Do not offer treatment to adults with non-malignant thyroid enlargement, normal thyroid function and mild or no symptoms unless:

• they have breathing difficulty or

• there is clinical concern, for example, because of marked airway narrowing.

Repeat thyroid ultrasound and TSH measurement for adults with non-malignant thyroid enlargement who are not receiving treatment, if:

• malignancy is subsequently suspected, or

• compression is suspected.

Consider repeating thyroid ultrasound and TSH measurement for adults with non-malignant thyroid enlargement who are not receiving treatment, if:

• the person's symptoms worsen or

• they develop symptoms, such as hoarseness, or shortness of breath.

For children and young people with non-malignant thyroid enlargement and normal thyroid function, discuss management with a specialist multidisciplinary team.

For adults with normal thyroid function and a cyst or predominantly cystic nodule with no vascular components, offer aspiration if it is causing compressive symptoms, with possible ethanol ablation if there is re-accumulation of cyst fluid later.

For adults with normal thyroid function and a non-cystic nodule or multinodular or diffuse goitre, consider the following if they have compressive symptoms relating to thyroid enlargement:

• surgery, particularly if there is marked airway narrowing or

• radioactive iodine ablation, if there is demonstrable radionuclide uptake, or

• percutaneous thermal ablation (see the NICE interventional procedures guidance on ultrasound-guided percutaneous radiofrequency ablation for benign thyroid nodules).