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Thyroid problems

Your thyroid controls how your body uses energy. If your thyroid is underactive (hypothyroidism), it can slow down many body processes. If your thyroid is overactive (hyperthyroidism), it can speed things up too much. This may affect your heart, your lungs, digestion, and how your body handles medicines during surgery.

Good thyroid control before surgery helps keep you safe and supports a smoother recovery. If your thyroid levels are not checked and managed, your surgery might be delayed.

Risks of an underactive thyroid
  • Heart problems (including coronary heart disease and heart failure)
  • Bone problems (including osteoporosis)
Risks of an overactive thyroid
  • Eye problems (such as eye irritation, double vision or bulging eyes)
  • Pregnancy complications (such as pre-eclampsia, premature birth or miscarriage)
  • A thyroid storm (a sudden and life-threatening flare-up of symptoms)

For those with diagnosed thyroid problems, now – not just before surgery – is the best time to check your thyroid levels, if:

  • You’ve been advised to have them checked and haven’t yet
  • It’s been more than a year since your last test

What you need to do:

  • Take your thyroid medicine as prescribed
  • Attend routine reviews with your practice pharmacist, GP, or endocrinology team and follow the advice given during these reviews
  • Attend any tests or appointments as recommended by your hospital team
  • Tell your doctor or pharmacist if you notice symptoms of an underactive or overactive thyroid

Go here to access the NHS Wales 111 website to find out more about underactive thyroid.

Go here to access the NHS Wales 111 website to find out more about overactive thyroid.

Rydym yn croesawu gohebiaeth a galwadau ffôn yn y Gymraeg neu'r Saesneg. Atebir gohebiaeth Gymraeg yn y Gymraeg, ac ni fydd hyn yn arwain at oedi. Mae’r dudalen hon ar gael yn Gymraeg drwy bwyso’r botwm ar y dde ar frig y dudalen.

We welcome correspondence and telephone calls in Welsh or English. Welsh language correspondence will be replied to in Welsh, and this will not lead to a delay. This page is available in Welsh by clicking ‘Cymraeg’ at the top right of this page.