Anxiety With Hashimoto's or an Underactive Thyroid: Is It Connected?

There does seem to be a link between thyroid conditions and anxiety, but it is not simple. Studies of people with Hashimoto's have found anxiety disorders more often than in people without it, even when thyroid levels are normal, although large population studies are less certain. Separately, a thyroid dose that is too high can cause anxiety-like symptoms. What matters most is that anxiety is taken seriously, checked properly, and treated with care that works.

If you live with Hashimoto's, an underactive thyroid or life after thyroid surgery and you feel anxious, you are not imagining it, and you are not alone. This guide explains what is known, what is worth checking, and where to get support.

If you are in crisis or feel unsafe, call 000. For 24/7 crisis support, call Lifeline on 13 11 14, or text 0477 13 11 14.

What the research shows

Several reviews have found anxiety is more common alongside autoimmune thyroid disease:

• A 2018 review in JAMA Psychiatry found higher odds of both depression and anxiety disorders in people with autoimmune thyroiditis.
• A 2024 review of people with Hashimoto's and normal thyroid levels found higher odds of anxiety disorders too, suggesting the link is not only about hormone levels.
• But a 2026 review of large population studies, covering more than 670,000 people, found the links for an underactive thyroid and for thyroid antibodies were not statistically significant, and called the evidence inconclusive.

So the honest summary is that the connection is real enough to take seriously, but nobody has shown that Hashimoto's or thyroid antibodies cause anxiety. Researchers are still working out why the two so often appear together.

When your thyroid dose is the issue

This is the most practical thing to check. Too much thyroid hormone can feel a lot like anxiety. The Australian prescribing information for levothyroxine lists anxiety, nervousness, a racing or pounding heart and trouble sleeping among the signs of a replacement dose that is too high. A 2026 review found these effects show up mainly when TSH is suppressed (pushed very low), not when the dose is right.

An underactive thyroid tends to bring low mood, tiredness and slowness rather than anxiety, but people's experience varies. If you have started medication or changed your dose recently and feel newly on edge, ask your doctor to check your thyroid tests. Do not change your dose yourself. As the consumer medicine information says, do not change your dose unless your doctor tells you to.

Feeling unsettled even with normal results

Many people on levothyroxine with normal results still do not feel themselves. In a large UK community study, people on thyroid medication with a TSH in the normal range reported more psychological distress than people of the same age and sex who were not on it. This is not in your head. It is a recognised gap, and it is worth raising rather than living with.

After thyroid surgery or thyroid cancer

Anxiety after thyroid cancer is common, and often under-recognised. In a Swedish study, three in four people reported fear of the cancer coming back around the time of diagnosis, and interviews describe an anxiety that is "partially hidden" behind a good prognosis. Australian research with thyroid cancer survivors found that many felt their ongoing concerns were dismissed or minimised by clinicians, and few were offered support beyond their treating doctors.

If that sounds familiar, it is reasonable to ask for more support. Being told you were lucky does not make the worry go away.

Other things that can feed anxiety

• Caffeine. healthdirect notes that caffeine can increase anxiety and disrupt sleep in some people. If you take thyroid medication, keep your coffee at least 30 minutes, and ideally 60, after your tablet. Our guide to coffee and thyroid medication explains why.
• Sleep. Poor sleep and anxiety feed each other. Good sleep habits matter more than any single product.
• Low iron. Low iron is common alongside an underactive thyroid and Hashimoto's, and in one large study people with iron-deficiency anaemia had higher rates of anxiety. It is worth having your iron checked if you are also tired.

What actually helps

Anxiety is very treatable. healthdirect lists cognitive behaviour therapy (CBT) among the most effective approaches, along with other talking therapies and online programs for mild to moderate anxiety. Regular movement, relaxation and good sleep help too.

Your GP is the place to start. Through Medicare's Better Access initiative, a GP can prepare a mental health treatment plan that may give you Medicare rebates for up to 10 individual sessions a year with a psychologist or other eligible provider. Your GP can also check your thyroid tests and rule out other physical causes at the same time.

Where to get support

• Emergency: 000.
• Lifeline (24/7 crisis support): 13 11 14, or text 0477 13 11 14.
• Beyond Blue (24/7 counselling): 1300 22 4636, or chat online.
• Your GP: for a check-up, your thyroid tests and a mental health treatment plan.

Questions to ask your doctor

1. Could my thyroid dose be too high or too low? What were my latest TSH and free T4?
2. Did this start after a dose change?
3. Should we check anything else, such as iron?
4. Would a mental health treatment plan or a referral for talking therapy help me?
5. Are any of my medicines or supplements likely to be making it worse?

A note on supplements

Be cautious with products sold for stress or anxiety. Some, such as ashwagandha (withania), may raise thyroid hormone levels, and the TGA has issued safety advice about a rare risk of liver injury from it. Check anything new with your doctor or pharmacist first. Our guide to supplements to avoid with an underactive thyroid covers this.

Where ThyroBase fits

ThyroBase is not a treatment for anxiety, and no nutrition product should be. It is a daily morning and evening nutrition powder for people living with Hashimoto's, an underactive thyroid or no thyroid, with no added caffeine, designed to sit alongside your thyroid medication, never instead of it. If you are anxious, the steps in this guide come first. Here is who ThyroBase is, and is not, designed for.

Feeling anxious with a thyroid condition is common, and it deserves proper care.

Ask for your thyroid to be checked, and ask for support for the anxiety itself.

Frequently asked questions

Can Hashimoto's cause anxiety?

Studies have found anxiety disorders more often in people with Hashimoto's, even with normal thyroid levels, but large population studies are less certain and nobody has shown that Hashimoto's causes anxiety. Either way, anxiety deserves to be taken seriously and treated. Talk to your GP.

Can levothyroxine cause anxiety?

A dose that is too high can cause anxiety, nervousness, a racing heart and trouble sleeping, according to the Australian prescribing information. These effects mainly happen when TSH is pushed very low. If you feel newly anxious after starting or changing your dose, ask your doctor to check your thyroid tests. Do not change your dose yourself.

Why do I feel anxious when my thyroid results are normal?

Many people on thyroid medication with normal results still report distress, and anxiety can have many causes, including caffeine, poor sleep, low iron and life stress. It is worth raising with your GP, who can check your tests and discuss support such as talking therapy.

Where can I get help for anxiety in Australia?

Start with your GP, who can check for physical causes and may prepare a mental health treatment plan. Beyond Blue offers 24/7 counselling on 1300 22 4636. For crisis support, call Lifeline on 13 11 14, and in an emergency call 000.

The honest takeaway

Anxiety and thyroid conditions often travel together, though the reasons are still being worked out. Check the practical things first: whether your dose is right, your caffeine and sleep, and your iron. Then treat the anxiety itself with care that works, starting with your GP. You deserve to feel steady, not just to have normal numbers.

ThyroBase is a nutritional supplement and is not intended to diagnose, treat, cure, or prevent any disease. It is designed to sit alongside your thyroid medication, not replace it. This article is general information, not medical or mental health advice. Never start, stop or change a supplement or prescription medication without speaking to your doctor or pharmacist first.

References

Siegmann EM, Müller HHO, Luecke C, et al. Association of depression and anxiety disorders with autoimmune thyroiditis: a systematic review and meta-analysis. JAMA Psychiatry. 2018;75(6):577-84 (correction 2019).
Wang B, Huang J, Chen L. Association between depression and anxiety disorders with euthyroid Hashimoto's thyroiditis: a systematic review and meta-analysis. Comprehensive Psychoneuroendocrinology. 2024;20:100279.
Ivens B, Bode H, Bschor T, et al. Thyroid disorders, thyroid autoimmunity, and anxiety: a systematic review and meta-analysis of population-based studies. PeerJ. 2026;14:e21446.
Eutroxsig (levothyroxine sodium) Consumer Medicine Information and Product Information. Australian Commission on Safety and Quality in Health Care, Medicine Finder. 2025.
Baskaran BS, Omrani MA, Muanda FT. Risk of cardiac, neuropsychiatric and musculoskeletal adverse events with levothyroxine: systematic review. British Journal of Clinical Pharmacology. 2026;92(4):1023-39.
Saravanan P, Chau WF, Roberts N, et al. Psychological well-being in patients on 'adequate' doses of l-thyroxine: results of a large, controlled community-based questionnaire study. Clinical Endocrinology. 2002;57(5):577-85.
Hedman C, Djärv T, Strang P, Lundgren CI. Fear of recurrence and view of life affect health-related quality of life in patients with differentiated thyroid carcinoma. Thyroid. 2018;28(12):1609-17.
Hedman C, Strang P, Djärv T, et al. Anxiety and fear of recurrence despite a good prognosis: an interview study with differentiated thyroid cancer patients. Thyroid. 2017;27(11):1417-23.
O'Neill CJ, Carlson MA, Rowe CW, et al. Hearing the voices of Australian thyroid cancer survivors: qualitative thematic analysis of semistructured interviews identifies unmet support needs. Thyroid. 2023;33(12):1455-64.
Lee HS, Chao HH, Huang WT, et al. Psychiatric disorders risk in patients with iron deficiency anemia and association with iron supplementation medications. BMC Psychiatry. 2020;20(1):216.
healthdirect Australia. Anxiety; Cognitive behaviour therapy (CBT). healthdirect.gov.au. 2024.
Australian Government Department of Health. Better Access initiative. health.gov.au. 2026.
Beyond Blue. Talk to a counsellor. beyondblue.org.au. Lifeline Australia. lifeline.org.au.
Therapeutic Goods Administration. Medicines containing Withania somnifera (Withania, Ashwagandha). Safety alert. tga.gov.au. 2024.