The thyroid gland is an endocrine gland in your neck. It makes two hormones that are secreted into the blood: thyroxine (T4) and triiodothyronine (T3). These hormones are necessary for all the cells in your body to work normally.
Thyroid disorders are very common and tend mainly to occur in women, although anybody – men, teenagers, children and babies, too – can be affected. About one in 20 people has thyroid disorder, which may be temporary or permanent.
Most common Thyroid disorders and symptoms
|Hyperthyroid (overactive thyroid)|| Hypothyroid (underactive thyroid) |
| Symptoms |
– weight loss
– heat intolerance
– sometimes, sore and gritty eyes
| Symptoms |
– Increased sensitivity to cold
– weight gain
– Puffy face
– poor concentration
– Muscle weakness
What is T3/T4/TSH?
T3 and T4 are hormones secreted by Thyroid gland. T3 and T4 are responsible for metabolism and growth of cell.
TSH (thyroid stimulating hormone) is simulated by Pituitary gland and is responsible for controlling T3 and T4 levels.
Under normal circumstances, if the T3/T4 level drops just a little below normal, the pituitary reacts by secreting TSH, and this hormone activates the thyroid gland to put out more T4 and T3.
Conversely, when the thyroid hormone levels rise above normal pituitary stops secreting TSH so that the thyroid gland stops working so hard and the secretion of T4 and T3 is reduced.
Your doctor will be able to get a good idea about the activity of your thyroid gland by listening to your symptoms, asking you some questions and by examining your neck. However, by taking a small sample of your blood he or she can assess exactly your thyroid secretory state. On this single sample of blood, for example, the levels of the hormones involved can be measured in the laboratory. By this means it is possible to find out if too much or too little T4 and/or T3 is being secreted, and how active the pituitary is by measuring the TSH. A single blood test will normally confirm the diagnosis, but sometimes other tests are required.