It seems that thyroid issues are being talked about more often these days, which unfortunately makes sense as there is evidence that the number of people with thyroid disorders is increasing, and that 10-12% of the population may suffer from some form of thyroid dysfunction (1, 2). The most common type of thyroid disorder is due to an underactive thyroid, called hypothyroidism (3). While there is a standard hormonal medication that can help, there are also a number of more holistic, functional approaches that can help to manage hypothyroidism and get the whole body into greater balance and health.
Thyroid Location and Function
The thyroid is a butterfly-shaped gland located in the middle of the lower neck, about an inch above the collarbones. While it is relatively small, it creates hormones called thyroxine (T4) and triiodothyronine (T3) that affect every cell, tissue, and organ, making it essential to each of your body’s processes (4, 5, 6). This is because thyroid hormones control how the body uses energy (also called the body’s metabolic rate) so it affects vital processes such as breathing, heart rate, digestion, mood and mental health, energy levels, and more (5). Because symptoms tend to develop slowly over months and years, it can be difficult to notice how bad symptoms have gotten until the thyroid is functioning very poorly. This also accounts for the high prevalence of people with thyroid dysfunction (up to 60% of all those who have thyroid problems!) who are undiagnosed (4, 5).
The thyroid also interacts closely with the pituitary gland. The pituitary gland secretes a hormone called the thyroid-stimulating hormone (TSH) that tells the thyroid the quantity of hormones it should produce and release (7).
The liver is similarly associated with the thyroid, though the relationship is more complex. The two hormones secreted by the thyroid differ in that T3 is active (and accounts for only 20% of thyroid hormones released), and T4 is an inactive prohormone (7). The liver plays an important role in metabolizing and transporting thyroid hormones, as well as transforming inactive T4 into active T3 (7, 9). Thyroid hormones similarly affect the liver, affecting its enzymes and metabolism, meaning that either thyroid dysfunction and/or liver dysfunction can negatively affect the other (9).
Hypothyroidism Causes and Symptoms
While the causes of primary hypothyroidism are mostly unknown, there are many links to other conditions that may cause secondary hypothyroidism. The biggest link is to Hashimoto’s disease, which is an autoimmune disorder that causes the immune system to attack the thyroid, resulting in poor hormone output (4, 5, 6, 8). In fact, autoimmune disorders are the cause of about 90% of the cases of hypothyroidism in adults (8). The link between thyroid issues and autoimmune disorders is very common, as the most common secondary cause of hyperthyroidism, known as an overperforming thyroid, is another type of autoimmune disease called Graves’ disease (3).
Other conditions such as inflammation of the thyroid (thyroiditis), congenital hypothyroidism (which is a genetic condition that is present at birth), or pituitary or liver disease can also lead to hypothyroidism (5, 9). Additionally, radiation treatment on the neck or chest, certain medicines such as those including lithium, surgical removal of all or part of the thyroid, or too much or too little iodine can also contribute to hypothyroidism (5, 6). Additionally, pregnancy can be a factor, though most cases of postpartum hypothyroidism resolve themselves with time (8).
The symptoms of hypothyroidism are many and varied and may show up differently for each person. They include (4, 5, 6, 7):
Joint and muscle pain, or muscle weakness
Heavy or irregular menstrual periods
Dry skin or dry, thinning hair