About the topic
An underactive thyroid makes too little thyroid hormone. Symptoms can develop slowly and include tiredness, feeling cold, constipation, dry skin and weight gain. Because these symptoms overlap with other conditions, blood tests are needed to help identify the cause.
Practical care & comfort
- Take prescribed thyroid replacement consistently, following the instructions given for your medicine.
- Attend blood tests so your clinician can check whether treatment needs adjustment.
- Check with a pharmacist before adding medicines or supplements, including iron or calcium.
Symptoms & signs
- Tiredness, feeling unusually cold or weight gain.
- Constipation, dry skin or hair changes.
- Slower thinking, low mood or a hoarse voice.
When to speak with a clinician: Arrange a review for suspected thyroid symptoms or symptoms that persist during treatment. Report troublesome side effects and any changes to your medicines. Do not change thyroid treatment without clinical advice.
Food & nutrition
These are medicine-timing issues, not reasons to remove nutritious foods. Ask a pharmacist about your own tablets and supplements.
Foods & nutrition to follow
- Keep a balanced diet with varied food groups.
- Follow your medicine's instructions about meals and caffeinated drinks.
Foods to limit or avoid
- Avoid taking calcium or iron supplements alongside thyroid medicine without timing advice.
- Do not use supplements as a substitute for prescribed thyroid replacement.
About this guide
General adult health information; it does not diagnose your symptoms or replace individual medical advice. Follow any plan your treating team has given you.
Further reading from the clinical sources used for this guide: