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NICE

NICE NG145 thyroid disease: assessment and management

This guideline covers the assessment and management of thyroid disease, including hypothyroidism, hyperthyroidism, and thyroid nodules, in adults, children and young people. It gives guidance on when to test thyroid function, how to interpret results, and how to initiate and monitor treatment. Note that NG145 was originally published in 2019; I am not confident there was a substantive 2023 re-issue, so I have focused only on content I am confident is stable across editions.

NICE2023 editionSummary
Official guidelineThyroid disease: assessment and management (NG145). NICE, 2023.
Read the official guideline · Checked for a newer edition on 2026-10-20
We do not reproduce the guideline text — this page is an independent summary.

Who it applies to

Adults, children and young people being investigated or treated for thyroid dysfunction in primary and secondary care.

Key recommendations

  • Use serum TSH as the first-line test when thyroid dysfunction is suspected, adding free T4 if TSH is abnormal.
  • Do not routinely offer thyroid function testing to asymptomatic adults, but consider it in people with relevant risk factors such as type 1 diabetes or other autoimmune disease.
  • Diagnose subclinical hypothyroidism using a raised TSH with normal free T4 on repeat testing before considering treatment.
  • Start levothyroxine for confirmed overt primary hypothyroidism and titrate the dose according to clinical response and TSH levels.
  • Recheck thyroid function roughly 6-8 weeks after starting or changing levothyroxine dose until a stable maintenance dose is reached.
  • Be cautious about treating subclinical hypothyroidism in older adults, since the evidence for benefit from levothyroxine in this group is limited.
  • Advise people on how to take levothyroxine consistently, such as on an empty stomach, and be aware of drugs and conditions that alter absorption or requirements.
  • Investigate thyroid nodules with ultrasound and use a risk-stratification approach to decide which nodules need fine needle aspiration cytology.
  • Refer to specialist endocrinology services for atypical presentations, treatment-resistant cases, or when there is diagnostic uncertainty.
  • Monitor people on long-term levothyroxine with periodic TSH checks once stable, rather than frequent routine retesting.

Practice points for students

  • TSH is the key screening test; free T4 is added only if TSH is abnormal, free T3 is rarely needed in routine assessment.
  • Levothyroxine dose changes need around 6 weeks before TSH re-equilibrates, so avoid checking too early.
  • Subclinical hypothyroidism does not always need treatment, especially in frail or older patients.
  • Thyroid nodules are assessed with ultrasound risk stratification before deciding on biopsy, not biopsied automatically.
  • NG145 does not cover thyroid disease management in pregnancy, which is addressed elsewhere.

Condition

Hypothyroidism

Other guidelines on this topic

Independent educational summary written by the WhiteCoat Pro editorial team with AI assistance and checked by a second AI model. It does not reproduce the guideline text, tables or figures, and it is not affiliated with or endorsed by NICE. It is not medical advice: always read the original guideline before applying it to patients.