What is included in this test profile?
TSH, FT4, FT3, TT4, Thyroid Peroxidase Antibodies, Thyroglobulin Antibodies, Vitamin D, Vitamin B12, Folate, Ferritin and CRP as well as Reverse T3, Cortisol, Magnesium + HbA1c.
Blood Test Explained
Please see below for a breakdown of test information, click each tab to find out more.
TSH (thyroid stimulating hormone) is a hormone manufactured in the pituitary gland (found in the brain). It s role is to stimulate thyroxine production in the thyroid gland (found in the neck). A high level within a health screening is associated with an underactive thyroid gland (hypothyroidism) and a low level is found if the thyroid gland is over-active (hyperthyroidism). Changes in the TSH level alone can indicate underlying thyroid problems even if the thyroxine levels are normal.
Free T4 (free thyroxine) is the active form of thyroxine, released from the thyroid gland in the neck. Its role is to control metabolism - release of energy from all cells of the body. A lack of thyroxine leads to, for example, tiredness and weight gain, whereas an excess will lead to weight loss, rapid heart rate and anxiety. It is generally believed that this level (FT4) is the most reliable indicator of thyroid status - ie whether the gland is over-active (hyperthyroidism) or underactive (hypothyroidism).
Free T3 (Free Triiodothyronine) - This is one of two hormones produced by the thyroid gland. This measures the level of T3 that is 'free' and is able to regulate metabolism.
Thyroid Peroxidase Antibodies This is an enzyme found in the thyroid gland mostly. This allows the production of thyroid hormones.
TT4 A Total T4 measurement measures ALL of the T4 hormone – bound and free. Most endocrinologists find “Free T4” more useful, but we still include T4 in this profile as some doctors still specifically request it when investigating thyroid function.
Thyroglobulin Antibodies Thyroglobulin is around half of the protein content for the Thyroid gland, which is used to store T4 and T3 Thyroid hormone molecules in the Thyroid. Conditions such as hyperthyroidism, Thyroiditis or goitre will cause an elevation of the serum Thyroglobulin. The main purpose of this testing is to indicate as a tumour marker for monitoring patients with differentiated thyroid cancer after a total thyroidectomy.
Reverse T3 There is controversy about the role of reverse T3 in thyroid illness. Conventional endocrinologists (hormone specialists) generally believe that knowledge of the level of this substance does not influence thyroid treatment decisions. The alternative view however is that reverse T3 is effectively 'antithyroid' - 'standard' T3 is the active thyroid hormone that stimulates the body's energy system (metabolism). Reverse T3 is a mirror image - it goes into cells, and instead of controlling metabolic processes it blocks the effect of T3. In this model, reverse T3 is effectively a hibernation hormone - in times of stress and chronic illness it lowers energy release from the cells - so normal thyroid levels with high reverse T3 may still result in hypothyroidism.
Cortisol As Cortisol decreases TSH, thereby decreasing thyroid hormone production, as well as inhibiting T4 to T3 conversion, measuring Cortisol is important and is now included in all Blue Horizon postal Thyroid Profiles.
Vitamin B12 is an important vitamin, essential for the normal functioning of many body processes. Deficiency can lead to anaemia (poor quality red blood cells) and neurological (nerve) disorders. It is most abundant in meat products so vegetarians are more vulnerable to deficiency of this vitamin. Pernicious anaemia develops if uptake of vitamin B12 into the blood from the gut is absent or severely impaired, and even if a diet rich in the vitamin is taken, deficiency will occur if this disease is present. Recent evidence suggests that mild deficiency is probably more common than previously thought. Mild deficiency may explain the presence of fatigue and a host of other limiting symptoms which is why we have included it within the PLUS V and PLUS X health screening profiles.
Vitamin D Vitamin D is an important vitamin, essential for good bone health. It is manufactured in the skin through sunlight exposure and is found in several foods. Prolonged Vitamin D lack can cause osteomalacia, a disease which causes severe structural deformities to the skeleton. Lower level Vitamin D deficiency can lead to a number of non-specific symptoms, including chronic pain, weak bones, frequent infections depression and fatigue. It has been estimated that between 50-70% of people living in the northern Europe (where daylight length reduces your chances of receiving adequate sunlight in the winter) are deficient in this vitamin by March each year which is why health screening for this important vitamin is essential.
Folate or Folic acid, is a B vitamin. It helps the body break down complex carbohydrates into simple sugars to be used for energy.
High values of this 'inflammatory marker' are associated with inflammation from some cause. It is not an exact test, it is nonspecific. Very high readings are associated with polymyalgia rheumatica, a painful muscle ache affecting usually the upper arms or legs, and temporal arteritis - inflammation of the temporal artery which usually presents with severe headache in the temple area. Arthritis and infection can also lead to a raised inflammatory marker.
is very important and relates to the Thyroid gland in many ways, in fact the thyroid cannot function without magnesium as it is responsible for helping make more T4 within the Thyroid gland. It also helps in converting inactive T4 into an active form of T3, this allows the metabolism of body cells which are enhanced by T3 (unlike inactive T4).
A deficiency in Magnesium has also been linked to goiter and/or enlarged thyroid gland.
Shortness/loss of breath
Feeling warm and sweating excessively
Irregular bowel movements
Feeling cold constantly
Weight gain and/or difficulty losing weight
Issues with Breathlessness
Low basal temperature
Low basal temperature
Dry hair and skin
Loss of libido
Blue Horizon Blood Test Reviews
Extremely efficient service from beginning to end. Procedure carried out quickly and efficiently. Results were very swift. Will be using again.UK
Impressed with speed of despatch after ordering. Kit and instructions very easy to understand and follow. Posted back to lab Monday morning, results received Wednesday morning, Thanks, may well be back soon.UK
As always, a superb service by all the BH team. Fast, efficient but very thoughtfuland caring of medical conditions, and associated patient mindset.. highly reccomended .cgUK
Utterly patient, kind and helpful, kit arrived next day, as did my results. 5 stars well-deserved.UK
Great service and product. The turn around is brilliant (mostly - there was a glitch during the early part of the Covid pandemic, but that seems to be resolved now). Tests are recognised by the medical profession so I am able to use the results to get the treatment I need without further tests.UK
I had various questions which they answered via email/webchat and the timing of getting a kit, sending it back and getting the results was good.UK