Could Your Thyroid Be Affecting Your Mental Health?
If you have been feeling unusually anxious, depressed, tired, irritable or mentally foggy, you may wonder whether your mental health is the only explanation.
Sometimes, physical health conditions can cause symptoms that overlap with mental health problems. One condition that healthcare professionals may consider is thyroid dysfunction.
Your thyroid is a small butterfly-shaped gland in the front of your neck, but the hormones it produces affect many systems throughout your body, including metabolism, energy levels, temperature regulation, the heart and brain. When thyroid hormone levels are too high or too low, some people may experience changes in mood, energy, sleep and concentration. (American Thyroid Association)
This does not mean that every case of anxiety or depression is caused by a thyroid problem. However, thyroid dysfunction can sometimes contribute to symptoms that look similar to mental health conditions. NICE recommends considering thyroid function testing in people with depression or unexplained anxiety when clinically appropriate. (Nice)
If your thyroid symptoms are also affecting your ability to fall asleep or stay asleep, understanding what insomnia is and how it affects your sleep can help you explore other possible causes of your sleep difficulties.
What Does the Thyroid Do?
The thyroid gland produces hormones that help regulate how your body uses energy and support the normal functioning of many organs, including the brain and heart.
The two main thyroid hormones are:
- Thyroxine (T4)
- Triiodothyronine (T3)
These hormones help control your metabolism and influence how quickly or slowly many processes in your body work.
When the thyroid produces too little hormone, this is known as hypothyroidism or an underactive thyroid.
When the thyroid produces too much hormone, this is known as hyperthyroidism or an overactive thyroid.
Both conditions can affect how you feel physically and emotionally.
Can Thyroid Problems Affect Your Mental Health?
Yes, thyroid dysfunction can be associated with symptoms that affect mood, energy, concentration and sleep.
For example:
- An underactive thyroid may be associated with feeling tired, low in mood, forgetful or mentally slowed down.
- An overactive thyroid may be associated with anxiety, nervousness, irritability, difficulty sleeping and restlessness. (American Thyroid Association)
However, these symptoms are not unique to thyroid problems.
Fatigue, anxiety, depression and poor concentration can also occur because of:
- Stress
- Depression
- Anxiety disorders
- Poor sleep
- Iron deficiency
- Medication side effects
- Other medical conditions
This is why symptoms alone cannot confirm whether your thyroid is responsible. A thyroid blood test is usually needed to investigate suspected thyroid dysfunction. (American Thyroid Association)
Underactive Thyroid and Mental Health
An underactive thyroid occurs when the thyroid does not produce enough thyroid hormone.
Because thyroid hormones help regulate many processes in the body, low hormone levels can cause the body to slow down.
Common symptoms of hypothyroidism may include:
- Feeling tired or exhausted
- Feeling cold
- Weight gain
- Constipation
- Dry skin
- Difficulty concentrating
- Memory problems
- Feeling sad or low
The American Thyroid Association lists feeling sad or down and forgetfulness among possible symptoms of hypothyroidism. (American Thyroid Association)
Can an Underactive Thyroid Cause Depression?
Depressed mood can occur in people with hypothyroidism, and research has found an association between overt hypothyroidism and depression.
However, the relationship is complex.
Having hypothyroidism does not automatically mean you will develop depression, and most people with depression do not have hypothyroidism. Depression can also continue even when thyroid hormone levels are corrected, meaning thyroid dysfunction is not always the only explanation for low mood. (American Thyroid Association)
This is an important message for anyone wondering:
“Is my depression caused by my thyroid?”
The answer may require a full assessment of both your physical and mental health.
If you are experiencing persistent low mood, loss of interest or other emotional changes, learning about the common signs and symptoms of depression can help you recognise when additional support may be appropriate.
Can Hypothyroidism Cause Brain Fog?
Many people with thyroid problems describe experiencing brain fog.
Brain fog is not a medical diagnosis, but people often use the term to describe symptoms such as:
- Difficulty concentrating
- Forgetfulness
- Feeling mentally slow
- Trouble finding words
- Difficulty focusing
Hypothyroidism can be associated with fatigue and forgetfulness, but these symptoms can also have many other causes. (American Thyroid Association)
If you regularly experience brain fog, especially alongside symptoms such as tiredness, feeling cold, constipation or unexplained weight changes, speak with a healthcare professional.
Overactive Thyroid and Mental Health
Hyperthyroidism happens when the thyroid produces too much thyroid hormone.
When there is too much thyroid hormone in the body, many processes can speed up.
This can lead to symptoms such as:
- Anxiety
- Nervousness
- Irritability
- Restlessness
- Mood changes
- Difficulty sleeping
- Feeling unusually energetic or restless
- A racing heartbeat
- Trembling
- Weight loss
An overactive thyroid can cause nervousness, anxiety, irritability and sleep difficulties. (American Thyroid Association)
Can an Overactive Thyroid Feel Like Anxiety?
Yes. Some symptoms of hyperthyroidism can overlap with anxiety.
For example, both anxiety and hyperthyroidism may involve:
- A racing heart
- Feeling nervous
- Restlessness
- Difficulty sleeping
- Shaking or trembling
- Sweating
- Difficulty concentrating
This overlap can sometimes make it difficult to know what is causing your symptoms without medical testing.
If you have anxiety symptoms alongside physical changes such as unexplained weight loss, heat intolerance, persistent palpitations or tremors, it may be worth discussing thyroid testing with a healthcare professional.
If you are unsure whether what you are experiencing is anxiety, learning what anxiety feels like and which symptoms are commonly associated with it may help.
Can Thyroid Problems Cause Panic Attacks?
A thyroid problem cannot be diagnosed based on panic symptoms alone, but an overactive thyroid can cause physical symptoms that may feel similar to anxiety or panic.
These can include:
- A rapid heartbeat
- Sweating
- Trembling
- Nervousness
- Difficulty sleeping
Because these symptoms overlap, it is important not to assume that panic-like symptoms are always caused by anxiety alone.
A healthcare professional can assess your symptoms and determine whether thyroid testing or other investigations are appropriate.
If you experience sudden episodes of intense fear together with physical symptoms, you can learn more about what a panic attack feels like and the symptoms people commonly experience.
Thyroid Problems and Sleep
Your thyroid can also affect your sleep.
Underactive Thyroid and Sleep
An underactive thyroid may contribute to:
- Extreme tiredness
- Low energy
- Changes in sleep patterns
However, feeling tired does not always mean that you will sleep well.
Some people may experience tiredness alongside other sleep difficulties caused by stress, anxiety or other health conditions.
Overactive Thyroid and Insomnia
An overactive thyroid can cause symptoms such as:
- Restlessness
- Anxiety
- A racing heartbeat
- Difficulty relaxing
- Difficulty sleeping
These symptoms may make it harder to fall asleep or stay asleep. (American Thyroid Association)
When anxiety and physical symptoms occur together, they can make it particularly difficult to switch off at night; learn more about how anxiety can contribute to insomnia.
Thyroid Problems and Mood Swings
Mood changes can have many possible causes.
An overactive thyroid may be associated with:
- Irritability
- Nervousness
- Mood changes
- Feeling restless
An underactive thyroid may be associated with:
- Low mood
- Reduced energy
- Fatigue
- Difficulty concentrating
However, mood swings should not automatically be blamed on your thyroid.
Other factors can include:
- Hormonal changes
- Stress
- Anxiety
- Depression
- Sleep deprivation
- Medication
- Alcohol or substance use
- Other health conditions
A proper medical assessment can help identify possible causes.
Could Hashimoto’s Disease Affect Mental Health?
Hashimoto’s thyroiditis is an autoimmune condition and a common cause of hypothyroidism.
As thyroid hormone levels fall, symptoms of hypothyroidism may develop, including fatigue, low mood and difficulty with concentration.
People with Hashimoto’s may also have other conditions or factors contributing to symptoms. Feeling unwell does not necessarily mean that every symptom is directly caused by thyroid hormone levels.
The American Thyroid Association notes that people with treated thyroid disease may still experience symptoms such as fatigue, brain fog or low mood for a variety of reasons, even when thyroid blood tests are within the reference range. (American Thyroid Association)
This is why persistent symptoms deserve a broader assessment rather than automatically assuming that more thyroid medication is the answer.
When Should You Get Your Thyroid Checked?
You should speak with a healthcare professional if you experience persistent symptoms that could suggest thyroid dysfunction.
Symptoms that may justify medical assessment include:
- Persistent fatigue
- Unexplained anxiety
- Depression or low mood
- Unexplained weight gain or weight loss
- Difficulty sleeping
- Feeling unusually cold or hot
- Persistent palpitations
- Trembling
- Changes in bowel habits
- Hair thinning or hair loss
- Changes in your menstrual cycle
- A swelling in your neck
NICE recommends considering thyroid function testing when there is clinical suspicion of thyroid dysfunction and specifically advises considering testing in people with depression or unexplained anxiety. (Nice)
What Tests Check Your Thyroid?
A healthcare professional may arrange blood tests to assess thyroid function.
These commonly involve measuring:
- TSH (thyroid-stimulating hormone)
- Free T4
- Sometimes Free T3
Depending on the situation, other tests may also be considered, including thyroid antibody tests.
NICE notes that TSH is generally an appropriate first test when thyroid dysfunction is suspected, with additional thyroid hormone testing depending on the results and clinical situation. (Nice)
Can Treating Thyroid Problems Improve Mental Health Symptoms?
If thyroid dysfunction is contributing to symptoms such as anxiety, low mood or fatigue, treating the thyroid condition may improve some symptoms.
However, improvement is not always immediate.
NICE notes that symptoms can take several weeks or months to improve after treatment changes. (Nice)
It is also important to understand that not every mental health symptom is caused by thyroid dysfunction.
Someone can have:
- Hypothyroidism and depression
- Hyperthyroidism and an anxiety disorder
- Normal thyroid function and mental health symptoms
- Both a thyroid condition and another medical condition
This is why treating your thyroid should not replace appropriate mental health care when it is needed.
Can Thyroid Medication Affect Anxiety or Mood?
Thyroid hormone treatment needs to be monitored carefully.
Taking too much thyroid hormone can lead to symptoms associated with excess thyroid hormone, including:
- Anxiety
- Insomnia
- A rapid heartbeat
The American Thyroid Association notes that high levels of T3 can cause symptoms including rapid heartbeat, insomnia and anxiety. (American Thyroid Association)
Do not change your thyroid medication dose without medical advice.
If you think your medication is causing symptoms, contact your prescribing clinician or pharmacist.
Thyroid Symptoms vs Anxiety: How Can You Tell the Difference?
Unfortunately, it can be difficult to tell based on symptoms alone.
Anxiety may cause:
- Excessive worry
- Racing thoughts
- Panic
- Restlessness
- A racing heartbeat
- Difficulty sleeping
Hyperthyroidism may cause:
- Anxiety
- Nervousness
- Irritability
- A rapid heartbeat
- Trembling
- Sweating
- Difficulty sleeping
- Weight loss
Because there is significant overlap, blood tests may be needed to check whether thyroid dysfunction is contributing to your symptoms. (American Thyroid Association)
Frequently Asked Questions
Can thyroid problems cause anxiety?
An overactive thyroid can cause symptoms such as anxiety, nervousness and irritability. However, anxiety has many possible causes, so a thyroid problem should not be assumed without medical assessment. (American Thyroid Association)
Can an underactive thyroid cause depression?
Depressed mood can occur in hypothyroidism, but not everyone with hypothyroidism develops depression, and most people with depression do not have hypothyroidism. (American Thyroid Association)
Can thyroid problems cause brain fog?
Hypothyroidism may be associated with forgetfulness and fatigue, which some people describe as brain fog. However, brain fog has many possible causes. (American Thyroid Association)
Can thyroid problems cause panic attacks?
Some symptoms of hyperthyroidism, such as a racing heart, nervousness and trembling, can overlap with panic symptoms. A medical assessment can help determine whether thyroid dysfunction may be contributing.
Should I get my thyroid checked if I have anxiety?
NICE recommends considering thyroid function testing in people with unexplained anxiety when clinically appropriate. Speak with a healthcare professional about your symptoms and whether testing is needed. (Nice)
Can thyroid medication cause anxiety?
Too much thyroid hormone can cause symptoms such as anxiety, insomnia and a rapid heartbeat. Contact your healthcare professional if you are concerned about medication side effects, and do not adjust your dose without medical advice. (American Thyroid Association)
Final Thoughts: Could Your Thyroid Be Affecting Your Mental Health?
Your mental health and physical health are closely connected.
If you are experiencing anxiety, depression, brain fog, mood changes or persistent sleep problems, it is important to remember that there may be several contributing factors.
Thyroid dysfunction can be associated with symptoms affecting mood, anxiety, concentration and sleep, but thyroid problems are not the cause of every mental health symptom.
The most important step is to avoid self-diagnosing.
If your symptoms are persistent or affecting your daily life, speak with a healthcare professional. They can assess your symptoms, consider whether thyroid testing is appropriate and help you access support for both your physical and mental health.
At Care Craft Meds Now, we believe that understanding the possible connection between physical and mental health can help people ask better questions and seek the right support.
