The thyroid gland releases hormones that serve many functions. Primarily, your thyroid helps to regulate your body’s metabolism, which is the process of breaking down food and converting it to energy.
Your thyroid gland also plays a role in your brain chemistry. When the thyroid isn't functioning properly, it can affect your emotions. If you've recently experienced unexplained changes in mood or significant emotional ups and downs, then hyperthyroidism may be a cause.
In this article, we'll explore what hyperthyroidism is, how it affects your mood and possible treatment methods.
We make it easy for you to participate in a clinical trial for Hyperthyroidism, and get access to the latest treatments not yet widely available - and be a part of finding a cure.
Your thyroid gland is responsible for creating thyroid hormones that regulate your body's basic metabolism. A number of conditions can occur that cause the thyroid gland to produce the wrong amount of hormones and disrupt the proper balance in your body.
When the thyroid gland produces too much of its hormones, the condition is referred to as overactive thyroid or hyperthyroidism.
Causes
There are a number of conditions that can result in an overactive thyroid. These include:
Graves' disease: Graves' disease is an autoimmune disorder that causes your body's immune system to attack the thyroid. When under attack by this disease, the thyroid responds by over-producing thyroid hormones.
Thyroid nodules: Lumps on the thyroid are common and usually benign. However, they can produce thyroid hormones that may lead to an excess in your body.
Thyroiditis: This is the medical term for inflammation of the thyroid. When the thyroid gland becomes inflamed, it can respond by becoming overactive.
Excessive iodine consumption: Iodine is used by the thyroid gland to produce its hormones. If you consume too much iodine, it can disrupt the balance of the chemical in the thyroid and result in hyperthyroidism.
A pituitary gland tumor: Like lumps on the thyroid, these are typically benign. The pituitary gland is responsible for the hormone that tells the thyroid gland to produce its hormones. As a result, a pituitary gland tumor may produce too many of its hormones and thereby cause the thyroid gland to overproduce hormones in the same way.
Risk factors
There are a number of risk factors that increase your chances of developing an overactive thyroid. They include:
Female sex: Women are more likely to develop hyperthyroidism
Age: Those over 60 are at increased risk for the condition
Genetics: A family history of the condition increases your chance of developing it
Other health problems: Certain other health conditions, such as pernicious anemia,¹ type 1 or type 2 diabetes,² and primary adrenal insufficiency,³ can lead to hyperthyroidism
Nicotine use: Smoking cigarettes or using other nicotine products increases your chances of developing hyperthyroidism.
Pregnancy: There may be a slight increase in hyperthyroidism during pregnancy and for a few months after
Potential complications
Having an excess of thyroid hormones in your body can result in a number of complications. These complications vary in severity, and some can be life-threatening. Potential complications of hyperthyroidism include:
Hypothyroidism: Because the treatment of hyperthyroidism is designed to slow down the thyroid, it may put thyroid output below normal levels. This condition is known as underactive thyroid or hypothyroidism.
Osteoporosis: In addition to your basic metabolic rate, the thyroid also regulates bone metabolism. Healthy bone material is constantly breaking down and getting replaced with new bone. With hyperthyroidism, the bone takes longer to rebuild than to break down, resulting in net bone loss. This results in brittle bones that break easily, a condition known as osteoporosis.
Pregnancy problems: Women with untreated or undertreated hyperthyroidism are at a higher risk of having complications during pregnancy, including miscarriage, premature labor, low birth weight, and a condition known as pre-eclampsia, which is characterized by persistent high blood pressure during the pregnancy and post-partum period.
Atrial fibrillation and stroke: Hyperthyroidism can cause a condition called atrial fibrillation. This condition results in an irregular heartbeat. Sometimes, because the heart isn't properly pumping blood, there can be a pooling of the blood in the heart. When this pooled blood clots, the blood clots can make their way to the brain and cause a stroke.
Other heart problems: An excess amount of thyroid hormones forces the heart to pump faster and harder, causing an increase in your blood pressure and putting the heart under greater stress. This can lead to further heart problems.
Thyroid storm: If untreated, the amount of thyroid hormones in the body can reach dangerous levels. When this happens, it's called thyroid storm. This rare but dangerous complication requires immediate medical attention.
Outlook
Although there are potentially life-threatening complications due to hyperthyroidism, there are several very effective treatments for the condition. When detected early enough, the chances of those already rare complications are further reduced.
Overactive thyroid is known to cause various mood changes. Some of these effects, such as depression and anxiety, are extremely common.
According to one study,⁴ 60% of hyperthyroid patients experience anxiety disorders. The same study notes that 31%-69% of hyperthyroid patients experience depressive disorders. Other symptoms, such as manic episodes,⁵ are rare among people with hyperthyroidism but have been known to occur.
Emotion and mood-related symptoms of hyperthyroidism include:
Dysphoria (extreme unease and dissatisfaction)
Irritability
Mood swings
Lack of concentration
Manic episodes
Older people may experience additional symptoms from hyperthyroidism. One study⁶ shows a link between mental decline and thyroid function in middle-aged and elderly adults, including a decline in attention, memory, and memory alertness. However, the effects are less obvious than in those with an underactive thyroid (hypothyroidism).
Examples of emotional and mood changes
People with hyperthyroidism may experience various symptoms of emotional and mood changes. Typically, the more overactive the thyroid is, the more drastic your mood swings may be.
Examples of emotional changes include:
Restless feelings
Unexplained nervousness
Unusual irritability
Increased anxiety
Fatigue and depression are also related to hyperthyroidism but more often occur due to hypothyroidism.
In general, these emotional symptoms and mood swings will improve, along with physical symptoms, with effective treatment.
Why does hyperthyroidism affect mood?
The exact mechanisms of hyperthyroidism that cause mood changes are not yet known. However, scientists found a link⁷ between proper thyroid function and brain activity, including a balancing effect on the brain's serotonin system.
Serotonin is a chemical produced in the body that has been shown to regulate mood. A lack of this chemical is likely to result in symptoms of depression. In addition, one study⁸ found a link between this chemical and anxiety.
So, any relationship between thyroid function and the body’s regulation of serotonin may potentially explain why hyperthyroidism can affect a person’s mood.
Changes in mood and mental function aren't the only symptoms of hyperthyroidism. Although not everyone experiences all of the symptoms, some other warning signs that you may have an overactive thyroid include:
Increased appetite
Increased heart rate
Irregular heartbeat
Shaky hands
Muscle weakness
Unusual sweating
An inability to tolerate heat
Frequent bowel movements
Goiter, which is an enlargement of the thyroid gland
If you're experiencing changes in mood that align with the symptoms and examples above, it's important you see a doctor to understand the causes.
Many of the changes in mood can be reversed by proper treatment if hyperthyroidism is the underlying condition.
Aside from emotional effects, detecting hyperthyroidism early and getting treatment will help to avoid some of the serious complications that it may cause.
Diagnosis
The first thing your doctor will do to diagnose hyperthyroidism is ask about your symptoms and medical history, then perform a physical exam.
Next, if they suspect your symptoms may be caused by thyroid problems, they'll have blood tests done.
These blood tests will allow the doctor to see the level of thyroid hormones in your blood, as well as other hormones related to thyroid function. In some cases, the doctor may use imaging tests, such as ultrasound or MRI to get a better look at the thyroid gland itself.
Treatment
Depending on the severity of your hyperthyroidism and your unique circumstances, there are a number of treatment options for you and your doctor to consider:
Antithyroid medication These medicines reduce the amount of thyroid hormones produced by your body. Others block the effects of thyroid hormones. Your doctor will help you find the medication and dose that works best for you.
Radioiodine therapy: For this therapy, the doctor will give you radioactive iodine. This substance, taken orally, makes its way to the thyroid just as the regular iodine in our diets does. Once there, the radiation causes the thyroid gland to shrink.
Thyroid surgery: Your doctor may also recommend surgery to reduce the size of the thyroid or to remove it entirely.
Having unexplained changes in mood can be scary because it leaves you feeling as though you aren't yourself. Any unusual restlessness, nervousness, irritability, or anxiety should not go untreated.
If you experience these changes, it's important that you seek the advice of a medical professional to check for any underlying medical causes, such as hyperthyroidism.
If your doctor makes a diagnosis, they may be able to fix your mood levels and prevent more serious complications from occurring in the future.
Sources
Pernicious anemia | National Heart, Lung, and Blood Institute
Diabetes overview | (NIDDK) National Institute of Diabetes and Digestive and Kidney Diseases
Adrenal insufficiency & Addison’s disease | (NIDDK) National Institute of Diabetes and Digestive and Kidney Diseases
Thyroid hormones, serotonin and mood: Of synergy and significance in the adult brain (2002)
Serotonin engages an anxiety and fear-promoting circuit in the extended amygdala (2016)
Other sources:
Hyperthyroidism (Overactive thyroid) | (NIDDK) National Institute of Diabetes and Digestive and Kidney Diseases
We make it easy for you to participate in a clinical trial for Hyperthyroidism, and get access to the latest treatments not yet widely available - and be a part of finding a cure.