bloodwork
Hypothyroidism

ICD-10 E03 · Other hypothyroidism

Monitoring plan

National Institute for Health and Care Excellence (NICE) (2024) · NICE NG145

TSH
adults on levothyroxine · every 3 months until stabilised, then once a year
“Measure TSH every 3 months until the level has stabilised (2 similar measurements within the reference range 3 months apart), and then once a year” — NG145
Free T4
adults on levothyroxine with persisting symptoms · alongside TSH if symptoms persist
“Consider measuring FT4 alongside TSH if symptoms persist despite treatment” — NG145
Free T3
children aged 2 and over · every 6 to 12 weeks until stabilisation (children 2+)
“FT4 and TSH every 6-12 weeks until stabilization” — NG145

Related tests

Tests MedlinePlus lists under “Diagnosis and Tests” for this condition. A reference, not a monitoring plan — no targets and no testing schedule are implied. · MedlinePlus

TestListed as
Free T3 Triiodothyronine (T3) Tests
Free T4 Thyroxine (T4) Test
Triiodothyronine resin uptake (T3RU) Triiodothyronine (T3) Tests
TSH TSH (Thyroid-stimulating hormone) test

Sources

Monitoring frequencies from NICE NG145.