If you suspect a malfunction of the thyroid gland, it is very important to know what tests for hypothyroidism need to be done in order to correctly establish a diagnosis and start therapy.
This disease is caused by a decrease in thyroid function and too low synthesis of certain hormones by it. This pathological process manifests itself by slowing down all the processes that occur in the body: drowsiness, weakness, weight gain, slowness in speech and thinking, chilliness, lowering blood pressure, in women - menstrual irregularities.
What is the danger of the disease
In severe cases, a phenomenon such as myxedema in adults and dementia (cretinism) in children develop. Complications of this disease can be hypothyroid coma, severe damage to blood vessels and the heart: bradycardia, IHD, coronary artery atherosclerosis. Treatment of patients with hypothyroidism is carried out using artificially synthesized thyroid hormone.
Laboratory diagnostics
In order for a specialist to be able to accurately diagnose this pathology in a patient, it is necessary to take an analysis for hypothyroidism to establish the quantitative content of the hormones TSH, T3, T4, TRH in the blood and to determine whether antibodies to thyroid peroxidase are present in it.
Research on the development of such a disease can answer three main questions:
- Does the patient have hypothyroidism?
- What is the main cause of this pathology: thyroid gland, hypothalamus, pituitary gland or immune system?
- What degree of hypothyroidism is observed in a particular case?
Identification of all forms of hypothyroidism
So, tests are required for hypothyroidism.
To identify the ailment, it is first necessary to determine the content of the hormones TSH, T3 and T4 in the blood, where TSH is thyroid-stimulating hormone, T4 is thyroxine, T3 is triiodothyronine. Hypothyroidism is a condition in which the thyroid gland produces these hormones, but in very small quantities or does not produce them at all. T3 has greater biological activity than T4, but less iodine is spent on the processes of its production. This is used by the body when a person has iodine deficiency - the concentration of T4 becomes lower, the level of T3, on the contrary, increases. The patient can live in a similar condition for a long time, and this will not significantly affect overall health. However, the occurrence of very non-specific symptoms is possible: reduced performance, brittle nails, hair loss, excessive lethargy. Such manifestations are inherent in many diseases or quite ordinary conditions that are often observed in people, especially in the off-season, for example, the notorious hypovitaminosis or chronic fatigue. This form of hypothyroidism does not interfere with a person’s life, as a rule, he does not turn to a specialist and does not receive treatment.
If a person has a low level of these hormones - this is a sign of complete hypothyroidism. The severity of this disease can be determined by the severity of symptoms and the concentration of hormones in the blood.
What tests to pass with hypothyroidism are interesting to many.
Varieties
In the classical classification, the disease is divided into:
- latent - hidden, subclinical, mild;
- manifest - moderate;
- complicated is the most severe form in which coma can occur.
The last form includes myxedema, myxedema coma (myxedema + coma, provoked by hypothyroidism), as well as infant cretinism.
Hormone tests for hypothyroidism can help identify the disease at an early stage.
What are the TRG and TTG talking about?
Even normal thyroid hormone levels in all laboratory tests do not guarantee that the patient does not have hypothyroidism. For early detection or diagnosis of subclinical hypothyroidism, you need to check the level of TSH in the blood. This hormone, also called thyrotropic, is produced by the pituitary gland to stimulate the hormonal functionality of the thyroid gland. If its concentration is increased, this means that the body lacks hormones. In this case, even the normal T3 and T4 level in the analyzes does not satisfy all the needs of the body. This type of hypothyroidism is called hidden. For a subclinical or latent form of the pathological process, TSH in a blood test for hypothyroidism should be in the range from 4 to 10 mIU / L. If this level is higher, then this is the same disease, but in a more severe form. It should be noted that the TSH norm to 4 mIU / l is outdated, and in modern recommendations for this disease for doctors it was reduced to 2 mIU / l.
Pituitary pathology
This hormone is produced by the pituitary gland. To make this happen correctly, the hypothalamus stimulates it with the help of TRH. Experts use this fact to exclude or confirm the pathology of the pituitary gland as one of the causes of hypothyroidism. A patient with low TSH is given the drug TRH and changes in laboratory studies are noted. If the pituitary gland responds to the TRG command by increasing the concentration of thyroid-stimulating hormone and this happens on time, then the cause of the development of this disease is not in it. In cases where there are no reactions to the introduction of TRH by blood tests, this means that it is necessary to look for the cause of the decreased working capacity of the pituitary gland. After that, in most cases, a diagnostic measure such as MRI is prescribed.
Indirectly, the pathology of the pituitary gland is also indicated by an insufficient number of its other hormones, laboratory studies of which can be carried out additionally. The level of thyroliberin (TRH) indicates the activity of the hypothalamus.
Analyzes of hypothyroidism for hormone levels are very informative.
Antibodies to thyroid peroxidase and other studies
Thyroperoxidase, thyroperoxidase, thyroid peroxidase, TPO are the various names of the only enzyme that is necessary for the production of the hormones T3 and T4 in the body. Specific antibodies suppress the enzyme peroxidase, which means that if you take an analysis for thyroid hormones, there will be a lack of them. If such antibodies are present in the blood in the analysis for thyroid hypothyroidism, this indicates that an autoimmune process develops in the body, and the ailment is provoked by autoaggression of the immune system.
A specific inflammation is considered an autoimmune process , so it is often characterized by inflammatory signs in laboratory studies. A simple blood test at the same time indicates an increase in the erythrocyte sedimentation rate, leukocytosis is quite possible, although not necessary. It all depends on how high the activity of the autoimmune process is in the body. Diagnostically significant concentration of anti-TPO is 100 U / ml or more.
What tests are needed for hypothyroidism, the doctor will tell.
Substantial damage to health
Hypothyroidism is the general condition of the body, so even its asymptomatic course is significantly harmful to health. As a result of such a pathological process, the level of triglycerides and cholesterol rises - this causes the development of atherosclerosis, which disrupts the blood supply through vasoconstriction. Hypothyroidism also provokes various forms of anemia - for example, hypochromic anemia with hemoglobin deficiency or normochromic with a low number of red blood cells. Creatinine concentration increases.
The mechanism of increased production of ALT and AST enzymes in hypothyroidism has not been reliably established, but this happens in almost every patient with a similar diagnosis. Pathology also captures other structures of the endocrine system, causing disturbances in the reproductive system, most often in women. At the same time, the amount of prolactin increases, which reduces the activity of gonadotropic hormones.
Receptor or peripheral hypothyroidism
This is a very rare form of the disease. Due to congenital abnormalities at the genetic level in humans, an inferiority of the thyroid hormone receptors is observed. In this case, the endocrine system tries to provide the body with the necessary hormones, but the cells are unable to perceive them. In this case, thyroid hormones are elevated, the pituitary gland begins to stimulate an already hyperactive gland, but the symptoms of hypothyroidism do not disappear. If all receptors are defective, then this condition is incompatible with life. Cases have been reported when in humans only part of the receptors is impaired.
In this case, experts talk about genetic mosaicism, when a certain part of the cells has a normal genotype, and part is inferior. Such a mutation is infrequent and its therapy has not been developed to date, so doctors need only use symptomatic therapy. In hypothyroidism, an analysis is also carried out for the content of TSH, T4 and T3 in the blood.