What to ask when your TSH is off

A quick note on what TSH tells us

TSH is the pituitary gland's signal to the thyroid. It rises when the body needs more thyroid hormone, and falls when there's plenty. It's a sensitive marker - but it's one piece of the picture, not the whole story. Context, symptoms, other results, and your individual history all matter. The questions below are conversation-starters, not self-diagnosis prompts.

If your TSH is high (above range)

A raised TSH often points towards the thyroid not producing enough hormone - but there's nuance, and the right response depends on your specific numbers, symptoms, and circumstances.

Questions to ask your clinician:

• How high is my TSH, and what does that level typically mean in practice?
• What was my free T4, and how does that fit with the TSH?
• Could this be a temporary fluctuation, or does it suggest a trend?
• Do I need any other tests - for example, antibody tests?
• If I'm already on levothyroxine, does my dose need reviewing?
• If I'm not yet on treatment, at what point would that conversation happen?
• How soon would you like to retest?
• Are there any symptoms I should watch for in the meantime?

If your TSH is low (below range)

A suppressed TSH can mean the thyroid is overactive - or that someone taking levothyroxine is receiving more than their body needs. The cause and implications are very different, so it's important to understand which is most likely in your case.

Questions to ask your clinician:

• How low is my TSH - mildly low, or very suppressed?
• What were my free T4 and free T3 results?
• Could this indicate hyperthyroidism, or is it more likely related to my current dose or treatment?
• Do I need any additional tests, such as TRAb or a scan?
• Are there any symptoms I should be looking out for?
• If I'm on levothyroxine, is a dose adjustment being considered?
• How quickly does a change in dose show up in blood tests, and when should we retest?
• Is there anything I should avoid or be cautious about while this is being investigated?

If your TSH is normal but you still feel unwell

A normal TSH does not automatically mean you'll feel well - and it's important to say so clearly at your appointment rather than assume your symptoms will be dismissed. Some people feel well with a TSH in the middle of the range; others feel better at a particular point within it. Some continue to have symptoms that don't have a simple thyroid explanation.

Questions to ask your clinician:

• My TSH is in range but I'm still experiencing [specific symptoms] - can we explore what might be contributing?
• Should we also look at my free T4 or free T3?
• Is there a particular part of the reference range where people tend to feel better, and is that relevant here?
• Could my symptoms have another cause worth investigating - anaemia, vitamin D, ferritin, or something else?
• Is there any value in checking TPO or other antibodies?
• What would you suggest as a next step given how I'm feeling?

Before your appointment

Use the questions tool to note your specific questions and bring them to your appointment. If you have your recent results, the lab results tool can help you see patterns over time - which is useful context for the conversation.

See also: Understanding TSH, T4 and T3 for plain-English background on what these markers mean.