If you have thyroid disease, you are likely blaming your thyroid whenever you experience constipation, weight gain, hair loss, brain fog or fatigue.
However, there are other symptoms that you may not have realized are also related to your thyroid’s under- or over-performance (Read: Don’t ignore these 11 most important thyroid symptoms)!
Let’s take a look at the connection between your thyroid and other symptoms, like:
- Impaired decision-making
- Fatty liver
Depression and hypothyroidism do share several common features. This includes cognitive dysfunction, psychomotor slowing, and apathy (Is it depression or hidden thyroid disease).
While hypothyroidism is not common amongst the people with depression, depression is fairly common amongst the group of patients with hypo- or hyperthyroidism.
Higher depression scores and lower quality of life scores in patients with euthyroid Hashimoto’s thyroiditis indicate that the actual autoimmune process can be contributing to poorer psychological well-being. This is true even when your thyroid hormone levels are at a normal level1.
Key Insight: Antibodies that attack the thyroid have also been seen to attack astrocytes in the brain.1 Astrocytes play an important role in nourishing neurons and as part of the blood-brain barrier.
There is some controversy over the association between antibodies and depressive symptoms.2 However, these studies often use different “normal” ranges for TSH or for thyroid antibodies. This can make the results difficult to compare.
Not only that, but the ranges are often not the optimal ranges that we use in the clinic. This makes the relevance of the study findings unclear.
Bottom Line: What is clearer is the increased risk during the postpartum period for both thyroid disease and for new-onset depression. Interestingly, increased TPO antibodies in early pregnancy are associated with three times the increased risk of first-onset depression postpartum.3
Being indecisive is one thing, but making poor decisions altogether is quite another!
In a study that came out just last year, researchers investigated decision-making abilities in patients with Graves’ disease compared to healthy controls4
When we make decisions, we can make them in two different contexts:
- We either know the consequences of our decisions, or
- We don’t know the consequences of our decisions.
This study looked at making decisions with a known risk involved. To do this, participants started with a certain amount of pretend money and played a computerized game. The goal was to have the highest amount of money at the very end.
In this game, dice are thrown and the participants have to guess what number will be rolled. If they guess one number the amount of money they can win or lose is greater than if they guess two, three or four numbers.
In the end, those with Graves’ disease had less “money” than the healthy controls. These results revealed that those with Graves’ made more guesses based on one number (more risky decisions) and did not use negative feedback as well as controls.4
Why Might This Be?
The authors propose dopamine dysfunction as one possible reason. This is due to the fact there is a connection between dopamine and decision-making.4
Tyrosine is an amino acid that we use to make both dopamine and our thyroid hormone. So the idea is if we are putting out excess amounts of thyroid hormone we might be using up the ingredients for making dopamine.
The authors do, however, acknowledge that there is currently a discrepancy in the research on whether dopamine levels decrease or increase in hyperthyroidism.4
It will be interesting to see the results of their next study on decision-making abilities after being successfully treated for hyperthyroidism.
Thyroid hormones are essential to many aspects of your overall functioning and this includes your brain. Just like we’ve discussed regarding depression and decision-making. A much rarer symptom is encephalopathy.
This can occur regardless of thyroid hormone levels, and as part of the autoimmune process. This thyroid-related encephalopathy manifests with symptoms, such as:
- Movement Disturbances
- Cognitive Impairment
- Changes in Consciousness
There are several stages of non-alcoholic liver disease ranging from non-alcoholic fatty liver all the way up to cirrhosis. This can be a life-threatening impairment of liver function.
There are a number of risk factors for liver dysfunction and one of these is thyroid disease.
A very large study of thousands of people found that the risk of fatty liver increases with increased TSH and risk decreases as free T4 increases.5 How does this affect your liver?
Well, part of this association was due to increased BMI and elevated triglycerides. When your thyroid is sluggish your weight creeps up, increasing your BMI. A sluggish thyroid also means it is hard for your liver to kick out excess lipids because key enzymes for this process to occur aren’t as active.
In another recent study, a closer look at patients with fatty liver disease revealed that those with poorer thyroid function as determined by higher TSH (even within conventional normal ranges) were more likely to have non-alcoholic steatohepatitis and fibrosis.6
This included patients with subclinical hypothyroidism. Ultimately, this association was found to be independent of other metabolic risk factors.6
If you have thyroid disease, working with your healthcare practitioner to identify your risks for fatty liver disease will allow you to lower your risks or get started on a care plan to get back on track (Fatty liver disease).
Abnormalities in thyroid hormone can also contribute to headaches.
In a very extreme example of this, there is a case report in the literature of four family members presenting to the emergency department with symptoms, like:
- Severe Headaches
- Rapid heartbeat7
Labs revealed extremely elevated free T4 hormones and suppressed TSH for all family members. None of them had antithyroid antibodies.
How did this occur? It turns out that the family had eaten beef neck. This is no longer legally sold in the United States because of historical problems with beef neck containing thyroid tissue.
When people consumed the beef neck with the thyroid tissue they would experience “hamburger thyrotoxicosis”.
Key Insight: Headaches can also be seen in hypothyroid states. When a group of hypothyroid or subclinically hypothyroid patients were followed over one year, headaches were reported by 34% of the patients.8
Common characteristics of these headaches included a pulsatile nature, nausea, vomiting, moderate to severe intensity and lasting between four and seventy-two hours.8
Treatment for hypothyroidism reduced the frequency of headaches in 78% of this patient population.8
There are fairly high rates of thyroid autoimmunity amongst those with fibromyalgia compared to the general population.12
One of the latest studies on the topic found that as many as 62% of the studied patients with Hashimoto’s thyroiditis also had fibromyalgia.13
Characteristics associated with having concomitant fibromyalgia were positive TPO antibodies, increased waist circumference, and a duration of thyroid disease.13 There were no significant differences in TSH between the patients with and without fibromyalgia.13
Bottom Line: There also appears to be some association between autoimmune thyroid disease and spinal pain as well as pain related to autoimmune connective tissue diseases.12
If you have been wanting children, but have not been able to conceive, it’s worthwhile to check on your thyroid health.
If your thyroid isn’t able to keep up with your own daily energy needs, think how much more it will struggle in trying to keep up with both you and a growing fetus!
Key Insight: Indeed, poor thyroid functioning is associated with higher rates of infertility, miscarriage and pregnancy complications.9 In women with unexplained infertility, as many as 27% have been found to have a TSH above 2.5 mIU/L.10
It’s not just women. Thyroid disease in men also affects their fertility. Although some of the human studies in this area are small.
Hyperthyroidism has been correlated with premature ejaculation while hypothyroidism has been correlated with low libido, delayed ejaculation, and erectile dysfunction.11 In addition to this, high or low levels of thyroid hormones also have an impact on semen quality.11
If your thyroid has been holding you back, there are steps you can take to improve both your thyroid health and fertility (The 7 ways your thyroid can affect your fertility).
Understand Your Thyroid, Optimize Your Health
Maintaining a happy, healthy thyroid is about more than your metabolism, weight, and digestion. It’s also about your mood, decision-making capacity, brain health, liver health, fertility and pain reduction.
Just another six reasons to give your thyroid a little TLC today!
1. Yalcin, M. M. et al. Is thyroid autoimmunity itself associated with psychological well-being in euthyroid Hashimoto’s thyroiditis? Endocr. J. 64, 425–429 (2017).
2. Fjaellegaard, K., Kvetny, J., Allerup, P. N., Bech, P. & Ellervik, C. Well-being and depression in individuals with subclinical hypothyroidism and thyroid autoimmunity—A general population study. Nord. J. Psychiatry 69, 73–78 (2015).
3. Wesseloo, R., Kamperman, A. M., Bergink, V. & Pop, V. J. M. Thyroid peroxidase antibodies during early gestation and the subsequent risk of first-onset postpartum depression: A prospective cohort study. J. Affect. Disord. 225, 399–403 (2018).
4. Dai, F., Yuan, L., Fang, J., Zhang, Q. & Wang, K. Impaired decision making under risky conditions in the acute phase of Graves’ thyroitoxicosis. Neurosci. Lett. 661, 1–4 (2017).
5. Bano, A. et al. Thyroid Function and the Risk of Nonalcoholic Fatty Liver Disease: The Rotterdam Study. J. Clin. Endocrinol. Metab. 101, 3204–3211 (2016).
6. Kim, D. et al. Subclinical Hypothyroidism and Low-Normal Thyroid Function Are Associated With Nonalcoholic Steatohepatitis and Fibrosis. Clin. Gastroenterol. Hepatol. 16, 123–131.e1 (2018).
7. Wartique, L. et al. An unusual cause of epidemic thyrotoxicosis. Acta Clin. Belg. 72, 451–453 (2017).
8. Lima Carvalho, M. de F., de Medeiros, J. S. & Valença, M. M. Headache in recent onset hypothyroidism: Prevalence, characteristics and outcome after treatment with levothyroxine. Cephalalgia 37, 938–946 (2017).
9. Gracia, C. Thyroid in Reproduction. Semin. Reprod. Med. 34, 315–316 (2016).
10. Orouji Jokar, T., Fourman, L. T., Lee, H., Mentzinger, K. & Fazeli, P. K. Higher TSH Levels Within the Normal Range Are Associated With Unexplained Infertility. J. Clin. Endocrinol. Metab. 103, 632–639 (2018).
11. Patel, N. & Kashanian, J. Thyroid Dysfunction and Male Reproductive Physiology. Semin. Reprod. Med. 34, 356–360 (2016).
12. Ahmad, J. & Tagoe, C. E. Fibromyalgia and chronic widespread pain in autoimmune thyroid disease. Clin. Rheumatol. 33, 885–891 (2014).
13. Haliloglu, S. et al. Fibromyalgia in patients with thyroid autoimmunity: prevalence and relationship with disease activity. Clin. Rheumatol. 36, 1617–1621 (2017).