Thyroid disease affects 1 in 20 people

Despite its small size the thyroid is an important organ playing an important role in controlling metabolism. It produces two hormones Thyroxine (T4) and Tri-iodothyronine (T3) and secretes them into the bloodstream.

The activity of the thyroid gland is normally under the control of the pituitary gland, a small pea-sized structure that hangs from the base of the brain.  Thyroid Stimulating Hormone (TSH) is produced by the pituitary gland and is responsible for regulating the production of T3 and T4 e.g. when T3 and T4 levels are low TSH stimulates the production of more and vice versa.   

The thyroid hormones are transported in the blood by proteins; T4 is present at higher levels and converts into the biologically active T3 form which can enter tissues and cells to carry out its metabolic functions.  The thyroid hormones are present in two different forms; Total were they are bound to proteins and Free.

Thyroid disease is common in the general population affecting about one person in twenty at some point in their life. All types of thyroid disease are more common in women than they are men and tend to run in families.  There are two main types of thyroid disease Hypothyroidism also referred to as under active thyroid and Hyperthyroidism (over active thyroid). Physical symptoms can include weight gain, lethargy, hair loss and joint pain. There are also several physiological symptoms associated with disorders of the thyroid some of which include diabetes, high cholesterol and high/low blood pressure.

The following are commonly tested when diagnosing thyroid disorders:

• Free T3 – levels are elevated in individuals with an overactive thyroid and low in individuals with an underactive thyroid.

• Total T3 - levels are elevated in individuals with an overactive thyroid and low in individuals with an underactive thyroid.

• Free T4 – levels are elevated in individuals with an overactive thyroid and low in individuals with an underactive thyroid.

• Total T4 - levels are elevated in individuals with an overactive thyroid and low in individuals with an underactive thyroid.

• TSH – levels are elevated in individuals with an underactive thyroid and low in individuals with an overactive thyroid.

Randox provide arrays containing all of the above mentioned analytes, for more information please visit the biochip immunoassay section of our site.