5 min|Dr. Maya Kuczma
Autoimmune Disease 101: What is Hashimoto's Thyroiditis?Immune Health
Know the Numbers
- Hypothyroidism is one of the most common chronic diseases worldwide (1)
- Hypothyroidism is more common in women than men, and incidence increases with age (2)
- In Canada, the most common cause of hypothyroidism is Hashimoto’s Thyroiditis (3)
A Healthy Thyroid
The thyroid is a small, butterfly shaped gland located in the front of our neck. In a healthy body, the hypothalamus produces thyrotropin-releasing hormone (TRH) to stimulate the pituitary gland to release thyroid-stimulating hormone (TSH). TSH ‘tells' the thyroid gland to produce more or less thyroid hormones - triiodothyronine (T3) and thyroxine (T4). T3 and T4 circulate through the body, affecting the health of our heart, skin, hair, intestines, brain, eyes, and metabolism. This entire cascade, from hypothalamus to the rest of the body, requires healthy hormonal signaling and response. The production of TSH requires protein, zinc, magnesium, and B12. The production of thyroid hormones requires many nutrients, including iodine, iron, zinc, and B vitamins.
Hypothalamus (TRH) —> Pituitary (TSH) —> Thyroid = T3, T4 —> heart, skin, hair, intestines, brain, eyes, metabolism
The thyroid gland predominantly produces T4, as well as a small amount of T3. T4 is then converted to T3 or reverse T3 (rT3). T3 is a much more potent thyroid hormone than T4; it stimulates our cell’s oxygen and energy consumption, directly affecting our metabolism. Conversion of T4 to T3 requires enzymes, as well as selenium and zinc.
T3 has to bind to receptors on our cells to have an effect. When these cells are healthy, and sensitive to this binding, T3 binds to a receptor on the surface of the cell, triggering a cascade of complex vital biological mechanisms. Cellular sensitivity is improved by many factors, including zinc, vitamin A, and exercise.
Evaluating the Thyroid
In order to measure the functioning of the thyroid gland, many Doctors test TSH levels. If the thyroid gland isn’t ‘listening’ to the signals from the pituitary, the pituitary will increase TSH release in an effort to create a ‘louder’ signal; this is reflected in an elevated TSH level. Once TSH elevates beyond the reference range, you may be diagnosed with hypothyroidism. Alternatively, if the thyroid is producing an excess of T3 and/or T4, the hypothalamus (and pituitary) respond by decreasing TRH and TSH, in an attempt to decrease the signal sent to the thyroid, thereby decreasing the production of thyroid hormones. This is known as a ‘negative feedback loop’. Once TSH drops below the reference range, you may be diagnosed with hyperthyroidism.
However, as we have learned from healthy thyroid physiology, TSH is only one component of a very complex system. By testing only TSH, we are evaluating one step in this system - how the pituitary is ’talking to’ the thyroid. It can be helpful to evaluate the entire thyroid cascade, by testing TSH, T3, T4, rT3, as well as thyroid antibodies, to fully evaluate the thyroid, and determine the cause of dysfunction.
Particularly in cases where TSH is abnormal, it is vital to examine whether the hypothyroidism or hyperthyroidism is the result of an autoimmune condition, such as Hashimoto’s or Graves’ disease.
In order to evaluate the health of your thyroid, your Doctor may order:
- Free T3
- Reverse T3 (rT3)
- Free T4
- Thyroid peroxidase antibody (TPO)
- Thyroglobulin antibody (TGAb)
- Thyroid stimulating hormone receptor antibodies (TSHRAb)
In cases of Hashimoto’s thyroiditis, TSH and thyroid peroxidase antibody (TPO) levels are elevated.
Elevated antibodies indicate an immune-mediated attack of the thyroid gland, known as autoimmunity. In cases of non-Hashimoto’s hypothyroidism, TSH will be elevated but antibody levels will appear normal. This is an important distinction to make, as autoimmune conditions require treatment that takes into account the entire thyroid cascade, as well as the immune system, whereas non-Hashimoto’s hypothyroidism typically only requires supportive treatment for the thyroid cascade. Additionally, Hashimoto’s thyroiditis may respond poorly, or symptoms may worsen, if the immune system is not accounted for within a treatment plan.
Symptoms of Hashimoto’s Thyroiditis
Symptoms of Hashimoto’s thyroiditis are primarily due to the lack of T3 and T4 production by the thyroid. Low levels of these hormones can cause many signs and symptoms, such as:
- Dry, brittle hair
- Hair loss, thinning eyebrows
- Dry skin
- Constipation, bloating
- Cold intolerance, cool extremities
- Fatigue, poor stamina
- Weight gain
- Poor concentration and memory
- Low heart rate, palpitations, and/or irregular heart rate
- Shortness of breath
- Hoarse voice
- Heavy menstruation
- Muscle soreness, weakness, joint pain
- Thyroid goiter
- Milky discharge from the breasts
In rare cases, immune-mediated destruction of the thyroid can cause the thyroid to fluctuate between states of hypo- and hyper- activity, leading to complex symptoms that mimic both Hashimoto’s thyroiditis and Graves' disease.(4)
Do you have many symptoms associated with hypothyroidism?
Have you been diagnosed with hypothyroidism, but your antibody levels weren’t tested? Are you on medication for hypothyroidism, but aren’t seeing improvement, or wonder if there’s more you could be doing to support you body?
At Integrative, we’re here to help. Contact our reception - (604) 738-1012 - or [email protected] to take a step towards better health and vitality!