- Underactive thyroid states (hypothyroidism)
- Overactive thyroid states (hyperthyroidism)
- Thyroid cancer
What is the thyroid and where is it located ?The thyroid is a butterfly-shaped gland that sits low on the front of the neck. Your thyroid lies below your Adam’s apple, along the front of the windpipe. It is part of the endocrine system and produces thyroid hormones.
Meet your thyroid hormones – who are they, what do they do and how are they controlled ?Thyroid hormones affect nearly every physiological process in the body and play vital roles in our:
- growth and development
- basal metabolic rate and metabolism of proteins, fats and carbohydrates
- heart function
- digestive function
- muscle control
- brain function
- bone health
- T4 (thyroxine)
- T3 (triiodothyronine) in small amounts
- Reverse T3 (rT3) in small amounts
- Tyrosine (an amino acid)
What is subclinical hypothyroidism ?Subclinical hypothyroidism exists when the thyroid is not working to its optimal capacity but is not underactive enough for the person to be diagnosed with a medical thyroid disease.
Why is subclinical hypothyroidism so prevalent?Subclinical hypothyroidism is so prevalent for the following reasons:
- Widespread mineral deficiencies such as Iodine and selenium
- Exposure to commonly encountered toxins such as those derived from plastics and those found in cosmetics. These chemicals are ubiquitous and every one of us is exposed to them. They are known as endocrine disruptors due to their ability to interfere with the regulatory processes that make our thyroid and other endocrine glands function properly.
- Current testing and screening for thyroid function often only picks up thyroid disease and misses those whose thyroid is underactive but not yet at a point where it can be “boxed” and labelled as a certain disease.
What blood tests are usually done to assess thyroid function ?The most common blood test marker used for assessing thyroid health is TSH (Thyroid Stimulating Hormone) which is produced by the anterior pituitary gland. Its job is to stimulate the thyroid to make thyroxine (T4). When TSH is higher than the reference range further testing is usually done.
What blood tests can be done to detect subclinical hypothyroidism ?The following blood test markers are useful to give a full picture of thyroid function:
- FreeT4 – measures how much free usable hormone is being produced by the thyroid
- Free T3 – measures how much of the T4 is being converted to the active T3
- Reverse T3 – measures how much T4 is being converted to the inactive Reverse T3
- Iodine – one of the main building blocks of thyroid hormone
- Zinc and selenium – needed to covert T4 to the T3
- Thyroid antibodies – if an autoimmune process is suspected