The short explanation
An overactive thyroid very commonly causes anxiety, restlessness, irritability, poor sleep and a racing heart. These are physical effects of too much thyroid hormone on the nervous system, not a weakness of character. Many people find these feelings ease as their thyroid levels come back towards normal with treatment, though it can take some weeks. Telling the people around you that this is part of the condition can help them understand.
What depends on your situation
The parts of this that change from woman to woman. Uncertainty is stated, not hidden.
- Some medicines used early in treatment can calm the racing heart and shakiness while the thyroid settles; your doctor can tell you whether that is suitable for you.
- If anxiety or low mood continues after your thyroid levels are normal, it deserves attention in its own right. Life stresses in the forties, perimenopause and poor sleep can all contribute.
- Talking therapy or counselling can help, and asking for it is common and sensible.
What this answer cannot determine
The boundary of online education. These need a clinician who can see you.
- This answer cannot tell you how much of what you feel is due to the thyroid. Your doctor can review your levels and symptoms over time.
Questions for your clinician
Take these with you. You can add any of them to an appointment card.
- Are my thyroid levels coming down, and when should my mood improve?
- Is there anything to help the anxiety and racing heart in the meantime?
- If I still feel anxious when my levels are normal, what then?
- Could perimenopause be adding to this?
When to seek help
Clinician-approved guidance for this topic. When in doubt, being seen is never the wrong choice.
Emergency — call 112 now
- Call 112 if you have thoughts of harming yourself, chest pain, or a very fast irregular heartbeat with breathlessness or fainting.
Get help the same day
- Get care the same day if you cannot sleep at all for several nights or feel unable to cope.
Book an appointment soon
- See your doctor within a few days if the anxiety is getting worse despite treatment.
Sources
The evidence this explanation is built on.
- Hyperthyroidism MedlinePlus (NIH)
- Overactive thyroid (hyperthyroidism) NHS
- Thyroid diseases MedlinePlus (NIH)
Who wrote and reviewed this
Every AskHer answer names its author. A clinically reviewed answer also names the clinician who signed it off — if no clinician is named below, it has not been clinically reviewed.
- Author
- AskHer Editorial (AI-assisted draft) AskHer's editorial team — not an individual clinician Works in English, தமிழ், हिन्दी
- Clinical reviewer
- Nobody yet No clinician has signed this answer off, and no person on the editorial team has read it yet. That is what the “Written with AI assistance” label means. It is queued for an editor to read, and then for a clinician who works in this area. The sources it was drafted against are listed above.
- Review status
- Written with AI assistance — not yet reviewed by a person
- Last reviewed
- Not yet reviewed by a person
- Version
- 1
Correction history
Substantive changes are listed, not quietly edited away.
No corrections have been made since this answer was first published.
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