Thyroid Monitoring

Thyroid hormone is produced in the thyroid gland; its function is to control many actions within the body including metabolism. Thyroid diseases can affect secretion of thyroid hormone either causing insufficient or excessive levels, causing symptoms of lethargy, weight gain, agitation or weight loss. Thyroid diseases are more commonly found in women than men, particularly following pregnancy or menopause.

The two main types of thyroid condition are hyperthyroidism and hypothyroidism which are caused by other conditions which affect the thyroid and its function.

Typical conditions leading to an excess of thyroid hormone (hyperthyroidism) are Graves’ disease, thyroiditis and overactive nodules. Whereas reduced thyroid hormone levels can be caused by conditions such as thyroiditis, Hashimoto’s thyroiditis and iodine deficiency.

Measurements of thyroid-stimulating hormone (TSH) are considered a first line test in adults with suspected thyroid dysfunction; based on the result, follow up tests would include free thyroxine (FT4), and free tri-iodothyronine (FT3) if TSH measurement was below normal ranges.

In addition to TSH measurements, for individuals with primary hypothyroidism, thyroid peroxidase (TPO) antibodies would be used as part of the initial investigations.