blood test for thyroid hormones - laboratory study measures the level of thyroid hormones produced by the thyroid gland.Thyroid hormones - are active substances that regulate metabolic processes in the body.They affect the cardiovascular system, gastrointestinal tract, reproductive or nervous system.
In some cases, prescribe a blood test for thyroid hormones?
doctor assigns the patient a blood test for the thyroid gland in the following cases:
- there are symptoms of hyperthyroidism (excessive production of thyroid hormones) or hypothyroidism (thyroid hormone deficiency);
- monitoring the effectiveness of treatment of hypothyroidism;
- a woman has no periods (amenorrhea)
- suspected female infertility;
- delayed sexual development of the child;
- mental retardation of the child;
- baldness (alopecia);
- decreased libido;
- cardiac arrhythmia.
symptoms of thyroid function are:
- a sharp increase or decrease in weight;
- irregular menstrual cycles;
- the emergence of problems with the scalp, skin and nails;
- memory impairment;
- hand tremor;
- excessive sweating;
- deterioration of mental processes;
- disruption of the cardiovascular system and gastrointestinal tract;
- irritability and tearfulness;
- reduced immunity.
How to donate blood for analysis?
To determine the level of thyroid hormone, a blood test is necessary to hand in the morning and on an empty stomach (the last meal should be 10-12 hours before blood sampling).Before you donate blood, it is advisable to sit quietly for 30 minutes.
just a few days before the blood test for thyroid necessary to eliminate physical exertion, alcohol, and try not to smoke.If you are taking iodine-containing drugs, or drugs that affect hormones, be sure to tell your doctor directs you to analyze.
Deciphering a blood test for thyroid hormones
results of a blood test for thyroid hormones include several indicators.Consider them all.
thyroid stimulating hormone (TSH) - produced by the anterior pituitary gland to affect the synthesis of thyroid hormones (T3, T4).If the index of TSH is elevated, it is possible that the patient has hypothyroidism, adrenal function poorly, there are mental illnesses or tumors of the pituitary gland.Hyperthyroidism - the main reason for low levels of thyroid-stimulating hormone.Also, the reason for the low level of TSH may be pituitary injury.TSH level is different from the reference, that is, the average indicates thyroid disease, even if all other indicators are normal.
triiodothyronine (T3) total - a hormone produced by the thyroid gland.It increases the oxygen consumption of all body tissues (except the brain), it stimulates the synthesis of vitamin A, and decreases blood cholesterol and accelerates the metabolism of proteins and activate the metabolic processes in the bone.The level of T3 is subject to seasonal fluctuations, for example, in the summer it is minimal.In people older than 65 years the concentration of the hormone in the blood decreases the total triiodothyronine.The total T3 can be upgraded with the toxic goiter, thyroiditis, post-partum thyroid dysfunction, chronic liver disease, weight gain, choriocarcinoma, nephrotic syndrome.Reducing the total T3 is observed in chronic liver disease, adrenal insufficiency, after suffering serious diseases, hypothyroidism, low protein diet, the reception of antithyroid drugs.
triiodothyronine (T3) free - thyroid hormone, stimulates the metabolism and absorption of oxygen by the tissues of the body.Analysis on the free T3 is performed to confirm the diagnosis of hyperthyroid.The reason for increasing the level of free T3 may be thyroiditis, toxic goiter, nephrotic syndrome, choriocarcinoma, chronic disorders of the liver, thyrotoxic adenoma.Reduction in the free T3 is associated with hypothyroidism, heavy physical exertion, adrenal insufficiency, a significant loss of body weight, protein-free or low-calorie diet, mental illness, recovery after serious diseases, the artificial thyrotoxicosis.
thyroxine (T4) total - the "main" thyroid hormone, which regulates the transport of proteins in the blood.Total T4 levels varies throughout the day: the maximum value is reached in 8-12 hours, the minimum - a 23-3 hours.Also, the total T4 is subject to seasonal changes.For example, its minimum value observed during the summer.During pregnancy, the concentration of thyroxine increases.Increased total T4 is observed in the following cases: tireotropinome, toxic adenoma, hyperthyroidism, nephrotic syndrome, chronic liver disease, thyroiditis, post-partum thyroid dysfunction, obesity, porphyria, HIV, taking certain medications.The disease is hypothyroidism, and receive certain drugs reduce the level of total T4.
thyroxine (T4) free - thyroid hormone are closely linked to transport proteins.Changes in the level of free T4 due to the dysfunction of the thyroid gland.The reasons may be increased thyroxine: thyroiditis, toxic goiter, hyperthyroidism, obesity, chronic liver disease, nephrotic syndrome, taking certain medications.The decline of free T4 is observed in hypothyroidism, after surgery, drastic weight loss, heroin use, contact with the lead receiving anabolic steroids.
Antibodies to thyroid peroxidase (TPO AT) - markers for determining a person predisposed to autoimmune diseases or not.Autoimmune disease - the main cause of hypothyroidism or hyperthyroidism.If blood tests for thyroid hormones are found AT TPO and high TSH levels, with a high probability we can assume that in the future people ill hypothyroidism.The level of antibodies in the blood increased in netireoidnyh autoimmune diseases, post-partum thyroid disorders, idiopathic hypothyroidism, toxic goiter.
Thyroglobulin (Tg) - a protein produced by the thyroid gland, which is a marker of tumors in her.Analysis on Tg cdaёtsya in the following cases: thyroid carcinoma, assessment of iodine deficiency status, confirmation of the effectiveness of the treatment of tumors of the thyroid gland, the establishment of an artificial hyperthyroidism.Thyroglobulin can be elevated in benign adenoma, hyperthyroidism, undertreated carcinoma, subacute thyroiditis.
thyroxine binding globulin (TBG) - a complex protein that transports the hormones T3 and T4.TSH value is increased in HIV infection, hypothyroidism, hepatitis, pregnancy, porphyria, taking certain medications.The reasons for lowering TSH may be: hypovarianism, acromegaly, intoxication, congenital deficiency of TBG, disturbance to the functioning of the kidneys, liver, gastrointestinal tract, hypoproteinemia, fever.
Reference Range of hormone levels in the blood depend on the age and sex of the patient.Therefore, only the endocrinologist can intelligently decipher a blood test for thyroid hormones.