Answers to questions we are often asked. This information is general and does not replace advice from your own doctor.
My TSH is normal but I still feel unwell. Is that possible?
Yes. A normal TSH does not guarantee that your tissues have enough active hormone. Conversion of T4 to T3 can be impaired, and reference ranges are wide. It is reasonable to ask for free T4 and free T3 to be tested alongside TSH.
What is the difference between T4 and T3?
T4 is mainly a storage hormone. The body must convert it into T3, the active hormone that does the work in your cells. Some people do not convert well and may need T3 as well as T4.
What is NDT?
Natural desiccated thyroid is a treatment made from animal thyroid that contains both T4 and T3. Some patients feel better on it than on synthetic T4 alone. Availability and prescribing vary.
Why are women affected more than men?
Autoimmune thyroid disease in particular is several times more common in women. Sex hormones, pregnancy and differences in immune function are thought to play a part, and risk rises around puberty, pregnancy and the menopause.
Can stress affect my thyroid?
Long term stress raises cortisol, which can reduce the conversion of T4 to T3 and blunt how cells respond to hormone. Managing stress and protecting sleep can support your thyroid health.
Which supplements matter for the thyroid?
Iodine, selenium, iron, zinc, vitamin D and vitamin B12 are the most relevant. Test before supplementing where you can, because both too little and too much can cause problems.
When should I take my thyroid medication?
Usually on an empty stomach, well apart from calcium, iron, coffee and certain other supplements and medicines, which can reduce absorption. Follow the instructions you are given and keep timing consistent.
Can I join the TPA forum?
Yes. Our forum is a supportive community of thyroid patients. You are welcome to join and share your questions and experience.
Does TPA give medical advice?
No. We provide information and peer support to help you have better informed conversations with your own doctor. We are not a substitute for medical care.