Thyroid hormone imbalances

• Thyroid hormones are crucial in helping the brain make new cells, particularly in the hippocampus, which is responsible for mood and memory [7]
• The conversion of T4 to T3 keeps brain cells active so we are mentally alert and our memory is functioning optimally [8]

• They regulate the production of many key neurotransmitter such as serotonin, dopamine, adrenaline and noradrenaline, which regulate our mood, metabolism, sleep, motivation, pleasure, arousal and energy levels [9]
• Conversely, neurotransmitters are needed to stimulate thyroid hormones
  • For instance, dopamine, the pleasure and reward neurotransmitter, stimulates the brain’s hypothalamus to release TSH (Thyroid Stimulating Hormone), which impacts production of T3 in the thyroid gland and helps to convert T4 to T3 in the brain
  • When thyroid function is low, dopamine levels released from the brain are also low, as they have a symbiotic relationship and need each other to function optimally [10]
  • It is important to test for dopamine deficiency when treating hypothyroidism [11]

• Thyroid hormones regulate breathing, metabolism and heart rate, and therefore have an effect on physical and mental energy levels — low levels of thyroid hormone can lead to depression and exhaustion [12]

• There is a symbiotic relationship between not only the hypothalamus, pituitary and adrenals, as represented by the HPA axis, but also between the thyroid and gonads
  • This system is known as the HPTGA axis – hypothalamus, pituitary, thyroid, gonads, adrenals
  • The hypothalamus sends a signal to the pituitary which sends it to the thyroid, gonads and adrenals as to how many hormones to produce
  • If the hypothalamus and pituitary are out of balance, then the thyroid, gonads and adrenals won’t work properly
• Low or borderline thyroid hormone will cause lower progesterone levels, because we need thyroid hormone to make pregnenolone (the mother hormone) which then makes progesterone
  • It is a vicious circle as low progesterone levels makes the thyroid gland work harder to produce more thyroid hormone [13]
  • Thyroid hormones make cells in our body more sensitive to progesterone uptake: when the cell’s progesterone receptor sites are not exposed to enough thyroid hormones, they can become resistant to progesterone [14] [15] [16]

Hypothyroidism is when the thyroid is underactive and doesn’t produce enough thyroid hormones (T3 and T4) to meet our body’s needs.

You can also have a “sub-clinical hypothyroid” meaning that you have symptoms of hypothyroidism, but your lab works are within the normal range. There is some evidence that lab ranges for thyroid are skewed by the inclusion of people suffering from thyroid imbalances in the numbers. [17]

Mental health symptoms of hypothyroidism

• Exhaustion
  • Despite sleep [18] [19]
  • Lack of ‘fight’ [20]
• Sleep issues
  • Such as hypersomnia or insomnia
• Anxiety [21]
  • Low thyroid can cause a rise in adrenal hormones such as adrenaline and cortisol, therefore hypothyroidism can make you feel anxious and stressed [22]
• Loss of libido [23]
• Depression [24] [25] [26]
  • In the US, experts link one third of all depression to thyroid imbalance [27]
  • In imaging studies, the hypothyroid brain looks remarkably like the depressed brain, and both show subtle changes in blood vessels, myelination (fatty insulation around nerves) and neurogenesis (nerve growth) [28]
  • Studies have shown that overall low brain function in hypothyroidism can lead to depression [29]
  • In one study of the elderly, ‘subclinical’ hypothyroidism increased the risk of depression by four times [30]
  • Mood disorders are increased in people with altered thyroid function [31]
  • Low-thyroid hormone levels reduce the function of serotonin receptors, which can lead to depression [32]
  • Hypothyroidism can often be misdiagnosed as bipolar disorder [33]
  • Hypothyroidism is one of the most commonly missed diagnoses and yet its incidence is increasingly widespread [34]
    • Doctors don’t check thyroid as a matter of course when a patient presents with depression [35]
    • Patients with thyroid imbalances are often put on antidepressants or institutionalised in psychiatric hospitals [36]
• Poor concentration and attention [37] [38]
• Poor memory
• Feeling ‘spaced out’
• Confusion
• Loss of mental acuity
• Irritability [39]

Physical symptoms of hypothyroidism

• Weight gain
• Sluggish digestion
• Constipation
• Sensitivity to cold or heat
• Cold hands and feet
• Dry, thinning hair
• Brittle nails
• Frequent colds and infections
• Muscle and joint aches and pains
• Headaches
• Fluid retention
• Pallor
• High cholesterol
• Low husky voice
• Lowered resistance to infection

[40] [41]

Causes of hypothyroidism

• Poor detoxification due to poor liver and gut function
• A sluggish pituitary gland
• Excessive estrogen
• Immune dysfunction
• Chronic stress and HPA dysregulation
  • According to Hyla Cass, hypothyroidism and related depression are on the rise due to the increase of people’s pace of life and daily stress [42]

[43]

Hashimoto’s thyroiditis is an autoimmune condition in which your immune system attacks your thyroid, which can result in hypothyroid symptoms. It is one of the most common causes of hypothyroid.

Over time the weakened thyroid cannot produce enough thyroid hormones (T3 and T4), and the pituitary gland increases levels of TSH to stimulate more thyroid hormone. This leads to higher levels of TSH, but lower thyroid hormones, resulting in hypothyroidism. [44]

It is diagnosed through a blood test analysing numbers of thyroid antibodies.

Mental health symptoms of Hashimoto’s

• Fluctuation between symptoms of underactive thyroid and overactive thyroid [45]

• Mood swings
• Bursts of energy or anxiety
• Sleep issues
• Heartbeat Irregularities
• Panic

Hashimoto’s disease is often misdiagnosed as bipolar disorder and, less frequently, as anxiety disorder. If left untreated, Hashimoto’s can lead to thyroid psychosis, also known as ‘myxoedema madness’. [46]

Causes of Hashimoto’s

Hashimoto’s can be due to:

• Environmental toxins
  • Which can trigger an inflammatory and immune response [47]
• Allergies or intolerance to foods, for instance gluten [48] [49]
  • Which can trigger an inflammatory and immune response
• Gut permeability
  • When the gut is permeable, large food molecules, bacteria, viruses etc. can travel into the bloodstream and cause a thyroid autoimmune reaction
• Poor diet
• Chronic stress and HPA axis dysfunction [50]

• Hyperthyroid is characterised by low TSH but elevated levels of free T3 or T4
  • However, there can also be subclinical hyperthyroid, characterised by low TSH but normal levels of T3 and T4 [51]
• An overactive thyroid means everything in your body is working too fast
• The body goes into hyperdrive, and levels of adrenaline and cortisol are higher in hyperthyroidism
• Chronic hyperthyroidism can cause the thyroid gland to burn out, causing hypothyroidism [52]
• The extreme pathology of hyperthyroidism is an autoimmune condition called Graves disease, where the thyroid attacks its own tissue and causes an excessive production of thyroid hormones

Mental health symptoms of hyperthyroid

• Feeling nervous and emotional
• Feeling jittery and on edge
• Anxiety
• Irritability
• Insomnia

Physical symptoms of hyperthyroidism

• Heart palpitations
• Increased trembling and shaking
• Increased pulse rate
• Night sweats
• Shortness of breath
• Weight loss or difficulty gaining weight
• Proptosis (bulging eyes)

[53] [54] [55]

• Women in perimenopause are more susceptible to suffering from thyroid problems [56]
• According to Sara Gottfried, “25% of women over 60 have antibodies against the thyroid. This is an important risk factor for future thyroid problems, as 11% of women with thyroid antibodies have hypothyroidism” [57]

• Thyroid problems are common during pregnancy and after giving birth, and hypothyroidism and thyroid antibodies can increase in the two year period after giving birth [58]
  • Thyroid problems are a major cause of postpartum depression, anxiety and psychosis
  • In one study 80-90% of postpartum depression was associated with a thyroid abnormality [59]
  • After childbirth, 7% of women develop postpartum thyroiditis — where the immune system attacks the thyroid causing
    • Mood swings
    • Exhaustion
    • Thinning hair
    • Insomnia [60]

Chronic stress and high cortisol are causes of thyroid imbalance. [61]

• When metabolic activity is high, the adrenals perceive this as stress and send a message to the hypothalamus. This causes the pituitary to produce less TSH, slowing down thyroid hormone production
• High adrenaline is linked to lower thyroxine (T4) which results in high thyroid-stimulating hormone (TSH) and symptoms of a sluggish thyroid
  • When that happens you may become thyroid resistant: you don’t respond properly to thyroid hormones, either endogenous or prescription medication, which means you may continue to have hypothyroid symptoms even if your blood tests, such as TSH, are normal
  • TSH and T4, the hormones routinely measured by doctors, do not adequately reflect what is happening inside your cells. One study found that normal reverse T3 predicted survival and physical functioning better than other thyroid blood tests, and that people with low serum T3 and high reverse T3 had worse physical performance associated with ageing [62]
• High cortisol causes you to make less free T3, the active thyroid hormone, and too much reverse T3 – which blocks thyroid hormone receptors
  • This is because when faced with stressors such as the flu, extreme cold, a car accident, hospitalisation, daily stress, or a vow to lose weight with calorie restriction, your metabolism will slow down by raising production of reverse T3 [63]
• HPA axis dysregulation
  • A healthy thyroid gland is dependent on healthy adrenal glands [64]
  • Any treatment for low thyroid must be accompanied by an investigation of adrenal function, [65] as hypothyroid symptoms could be due to poor adrenal function , and treating the adrenals can reverse hypothyroidism [66]
  • With hypothyroidism, the adrenals cannot have the same energizing effect on the brain, which can lead to low mood, lethargy and weight gain [67]
  • HPA axis dysfunction can cause inflammation which can lead to thyroid receptor resistance to thyroid hormone (therefore there can be enough thyroid hormone circulating, but it’s not affecting the cells), which can lead to poor intestinal motility. Inflammation can also lead to impaired gut permeability.[68]

Hypothyroidism is largely genetic.

• Iodine deficiency
  • All hormone receptors need iodine before they can use their hormones, but this is especially true of the thyroid
  • Hyla Cass suggests that in the US 12% of the population are deficient in iodine, which can be a cause of hypothyroidism [69]
• Food allergies (e.g. gluten intolerance) [70]
  • Food allergies and intolerances can cause inflammation in the gut, which in turn can cause leaky gut and systemic inflammation, which can cause auto-immune diseases such as Hashimotos
  • Inflammation in the gut can decrease the conversion of T4 to T3 thyroid hormones, causing hypothyroid symptoms [71]
• Mineral deficiency
  • For instance, selenium is essential for healthy thyroid function
• Lack of protein
  • Proteins are the building blocks of all hormones, including thyroid hormones
• Excess sugar
  • Excess sugar increases adrenaline and cortisol output
• Excessive goitrogens (substances which disrupt thyroid hormone production)
  • Raw cruciferous vegetables such as broccoli, cabbage, etc. can slow thyroid function
  • Soy can also act as a goitrogen
  • Cooking and fermenting can reduce these goitrogenic properties

[72]

Thyroid imbalance can be caused by synthetic chemicals and endocrine disruptors in our air, food, and water: [73]

• The current epidemic of thyroid problems is partly caused by the increase in toxic load on our bodies, and the negative impact of toxins and pollutants on our endocrine system [74] [75]
• Chemicals known as endocrine disruptors that affect either the hypothalamic-pituitary-thyroid (HPT) axis or thyroid receptors (and impact negatively on the conversion of T4 to T3) [76] are called thyroid disruptors, and include more than 150 industrial chemicals such as:
  • Industrial petrochemicals such as polychlorinated biphenyls (PCBs), Dioxins, BPA [77] [78]
  • Chlorine, fluoride and bromine from tap water
  • Bisphenol-A (BPA) can be found in canned food lining, plastic water bottles, flame retardants, mattresses, etc. [79]
  • Heavy metals such as lead, mercury, cadmium [80]
  • Herbicides and pesticides [81]
  • Chemicals found in cigarette smoke

Poor ability to detoxify due to insufficient liver and kidney function. [82]

Hypothyroidism is also often associated with other diseases and endocrine problems such as:

• Autoimmune diseases
• Chronic fatigue
• Immune dysfunction syndrome (CFIDS)
• Fibromyalgia
• Insulin-dependent diabetes

Blood tests for thyroid should measure:

• TSH (Thyroid Stimulating Hormone)
• T3 (tri-iodothyronine), T4 (active thyroid hormone)
• Most GPs check only TSH and T4 Thyroxine levels when patients take thyroid medication
  • We assume that when these levels are normal then the medication is adequate, but for patients who still have symptoms and want to feel better, we should also check T3 circulating thyroid hormone levels
  • If T3 levels are below the normal range, it could be an indication of Wilson’s syndrome, which means that the body is unable to convert T4 into T3 [89]
• Reverse T3
• Thyroid antibodies (thyroid peroxidase antibodies, thyroglobulin antibodies)
  • It is important to check thyroid antibodies as part of routine testing, as while a patient may present with normal TSH levels they may have autoimmunity against their thyroid which makes it function poorly [90]
• Liver function test, as T4 is activated in the liver
• Ferritin levels, as they enable T3 to reach the cells [91]
• Some researchers say that hypothyroidism can be diagnosed purely by raised cholesterol levels [92]

A good home test for hypothyroid is measuring your basal body temperature:

• For a woman menstruating, check your basal body temperature between day 2 and day 4 of your cycle
• Using a mercury thermometer (shake it down the night before so it is resting mode)
• In the morning place it under your armpit first thing and leave for ten minutes
• Record your reading
• Repeat the same action at the same time for 4 continuous days
• Be aware that temperature is higher close to or during ovulation
• Normal is between 97.8 and 98.2 degrees Fahrenheit, respectively 36.6 and 36.8 degrees Celsius

If your temperature is consistently below 97.8 degrees Fahrenheit (36.5 Celsius), this is evidence of low thyroid function. [93] [94]