Thyrotropin (TTH, TSH)
The thyrotropin test is needed for screening and diagnosis of thyroid diseases (it is the most sensitive indicator of thyroid dysfunction), for monitoring the treatment of hypothyroidism and hyperthyroidism, and for investigating the causes of female infertility.
Who needs a thyrotropin test?
The thyrotropin test is needed for screening and diagnosis of thyroid diseases (it is the most sensitive indicator of thyroid dysfunction), for monitoring the treatment of hypothyroidism and hyperthyroidism, and for investigating the causes of female infertility.
When should I be tested?
The test is recommended if you have symptoms of thyroid disease:
Symptoms of an overactive thyroid gland may include poor heat tolerance, weight loss, increased heart rate, nervousness, insomnia, shortness of breath, diarrhoea, trembling hands and eye irritation.
Symptoms of thyroid insufficiency include fatigue, weakness, weight gain, slow heartbeat and cold intolerance.
If the test is performed to monitor thyroid disease and the dose of the drug is changed/adjusted, it is recommended to repeat the test after 1-2 months as the TTH level should stabilise.
What sample is needed for the thyrotropin test?
Blood is drawn from a vein in the arm.
How to prepare for the survey?
There is no special preparation, but some medicines can distort the TTH results, so tell your doctor about the medicines you are taking.
What do my results mean?
High levels of TTH in the blood almost always indicate reduced thyroid hormone activity caused by thyroid insufficiency (hypothyroidism). Very rarely, a high TTH result indicates a disorder of the pituitary gland (post-brain gland) (e.g. a TTH-secreting tumour). They are called secondary hyperthyroidism. High TTH values are also common in people with hypothyroidism who are under-treated with thyroid hormones.
Low levels of TTH may indicate an overactive thyroid gland (hyperthyroidism) or a pituitary gland lesion affecting TTH production and excretion. Low TTH values are also common in people with hypothyroidism who are overmedicated with thyroid hormones.
Abnormal (too low or too high) TTH values indicate a deficiency or excess of thyroid hormones in the body, but do not reveal the cause of the disorder. If an abnormal TTH result is obtained, further thyroid tests are needed to find out what caused the increase or decrease in TTH levels.
Very severe stress and acute illness can affect TTH results. Low TTH values are possible in the first trimester of pregnancy.
Related studies
LT4, LT3, T4, T3, ATPO, thyroglobulin, antibodies to thyroglobulin
Related conditions/diseases.
Hypothyroidism, hyperthyroidism, pituitary tumour
You can consult our family doctors.
