TL;DR:
- TSH (thyrotropic hormone): Produced by the pituitary gland to stimulate thyroid hormone (T3, T4) production. Regulated by the hypothalamus-pituitary-thyroid axis.
- TSH importance: Maintains metabolism, cardiovascular function, thermoregulation, and calcium-phosphorus balance.
- Testing: Used to diagnose hypothyroidism (high TSH) or hyperthyroidism (low TSH). Normal adult range: 0.32–5.0 mlU/L; varies by age, pregnancy, and labs.
- Symptoms of abnormalities: High TSH includes fatigue, cold sensitivity, weight gain; low TSH includes irritability, sweating, diarrhea, palpitations.
- Causes in children: Often maternal thyroid issues, iodine deficiency, or pituitary disorders; untreated hypothyroidism can delay growth and mental development.
- Costs: Free with referrals; private tests cost PLN 18–200 depending on scope.
- Selenium: Recommended to support TSH function.
TSH is otherwise known as thyrotropic hormone, which is produced by the pituitary gland that stimulates the thyroid gland to produce and secrete thyroid hormones (T3 and T4). The pituitary gland is responsible for increasing TSH secretion if insufficient thyroid hormone levels occur, as well as due to the effects of adrenaline and vasopressin. Decreased thyroid secretion is said to occur when there is an excess of thyroid hormones. To detect hyperthyroidism or hypothyroidism, a test of the hormone is performed from the blood. The GP or endocrinologist should give the patient a referral for basic blood tests, or refer the patient for further diagnostics.
How does the TSH hormone work?
Thyroid gland is a small-sized gland that produces hormones in the body. It is located at the front of the neck in the lower part of the neck, and the thyroid gland consists of two lobes joined together (shaped like a butterfly). Both the thyroid gland, the pituitary gland and the hypothalamus are one common axis that depends on each other and works as a coupled system. The hypothalamus allows the production of the hormone TRH, which in turn stimulates the pituitary gland to produce TSH. TSH, in turn, is responsible for stimulating the thyroid gland to produce hormones. Each of these organs is directly related to each other. However, the main role is played by the hypothalamus, the central part of the nervous system. When hormone levels are too high, the hypothalamus stops producing TRH and the pituitary gland stops producing TSH. As a result, hormone production stops. The hypothalamic-pituitary relationship, however, affects the proper functioning of other glands, including the ovaries, testes and adrenal glands. This is why prevention and TSH testing is so important, especially in ladies who wish to become pregnant. Proper TSH levels are responsible for maintaining metabolism, cardiovascular function, calcium-phosphorus balance, or thermoregulation of the body.
What significance does TSH play in the body?
The hormones that the thyroid gland produces have a huge impact on the proper functioning of the body. Too high or too low TSH can be a serious cause of thyroid dysfunction. This, in turn, affects both mood and weight maintenance. Thyroid disease diagnosis is mainly concerned with testing for hypothyroidism and involves determining serum TSH levels. This is the most sensitive indicator, which is why TSH testing is one of the first tests ordered for patients to perform. A result between 02 – 04 mj.mm/l and 4.0 – 4.5 mj.mm/l means that the thyroid gland is most likely working properly. However, it is worth remembering that the amount of TSH concentration in the body is an individual issue that depends on the age of the patient and even the time when the blood sample was taken. Endocrine diseases are a very broad group of conditions that affect not only the organs responsible for the production of hormones, but also many other systems. The symptoms and complaints of each endocrine disease can vary widely.
What are the norms of TSH levels?
The normal norms of TSH concentration depend on the age of the patient and are respectively:
- Immediately after birth, TSH should oscillate between 1.3 – 19.9 mlU/L,
- On the third day of life 1.1 – 1.7 mlU/L,
- After 10 weeks in children – 0.6 – 10 mlU/L,
- In 14-month-old children – 0.4 – 7.0 mlU/L,
- In children aged 5 years – 0.4 – 6.0 mlU/L,
- In children under 14 years of age should not exceed 4.0 – 5.0 mlU/L,
- In adults – 0.32 – 5.0 mlU/L.
- In pregnant women in the first trimester a maximum of 2.5 mj/L, in the second trimester a maximum of 3.0 mlU/L, and in the third trimester from 0.1 to 3.0 mlU/L.
The TSH standards, however, may vary at each laboratory performing the tests. Therefore, always consult your results with your family doctor or endocrinologist.
When is a TSH test performed?
TSH hormone testing is usually performed when there are symptoms indicating hyperthyroidism or hypothyroidism. Indications for testing may also include such ailments as:
- Suspected thyroid dysfunction,
- Chronic diarrhea,
- Cardiac arrhythmias,
- Sudden weight loss despite a large appetite,
- Anxiety and irritability,
- Agitation,
- Swelling,
- Increased body weight.
The dominant function over the endocrine system is performed by the hypothalamus with the pituitary gland (tropic hormones). They allow to control the production of other hormones in the body. If hypothyroidism occurs, the required amount of tropic hormones is increased due to the body's stimulation of the inactive gland to work. In primary hypothyroidism, on the other hand, the situation is reversed. Tropic hormones decrease as a result of the inhibition of the hyper active gland. To support the work of TSH and the proper functioning of this hormone, selenium supplementation is recommended in the first place. This micronutrient plays a special role, as it is part of the production process of thyroid hormones.
What is the interpretation of TSH concentration results?
Correctly interpreting TSH results is not the easiest task, even when the values for the test are given. Elevated TSH can indicate problems with hypothyroidism, while an underestimated result usually indicates hyperthyroidism of this gland. If the TSH results are not correct, then the doctor should order further diagnosis of ft3 and ft4 levels.
What does too high TSH mean?
Too high TSH levels in the blood usually indicate hypothyroidism, which occurs when the thyroid glands, despite their stimulation by the pituitary gland, do not produce enough hormones. High TSH levels can also indicate tertiary hypothyroidism, which is when the hypothalamus is damaged and TRH production ceases. Excessive TSH levels can also indicate problems such as pituitary adenoma, genetically determined diseases, primary adrenal insufficiency and taking certain medications. In pregnant women, hypothyroidism of this gland can lead to miscarriage or premature birth. High TSH levels can be recognized by characteristic symptoms, which include a constant feeling of cold, fatigue, headache, joint pain, sudden weight gain, body water retention, depression, concentration problems.
What does too low TSH mean?
Too low a THS level is usually a signal of an existing hyperthyroidism Sometimes it also indicates hypopituitarism. The latter condition occurs when the pituitary gland does not produce TSH, and as a result, the thyroid gland does not get any information that there is a deficiency of thyroxine and triiodothyronine in the body. Low TSH can also indicate Graves-Basedow disease, as well as conditions such as acute psychiatric syndrome, post-thyroid syndrome, old age and taking certain medications. Symptoms that may indicate hyperthyroidism are mainly nervousness, excessive sweat production, mood swings, irritability, diarrhea, hand tremors, menstrual disorders, or palpitations.
What are the causes of abnormal TSH levels in children?
In the case of elevated TSH in children, the main causes of problems are thought to be maternal thyroid abnormalities during pregnancy, abnormalities in the child's thyroid structure, taking a drug that affects thyroid function, iodine deficiency in fetal life, or a tumor in the pituitary gland. However, it is worth remembering that in premature babies and newborns, TSH levels can normalize within a few days, so long-term therapy is not always necessary. If, on the other hand, the level of concentration persists for a long time, then it is necessary to include appropriate therapy. Untreated hypothyroidism can even cause mental retardation. Hypothyroidism of TSH in children usually manifests itself in the form of a smaller appetite, delayed growth, hoarseness, constipation, delayed teething, facial swelling, or hair loss. In contrast, excessively low TSH in the youngest is most often due to pituitary disorders, Hashimoto's disease and Graves-Basedow disease. Treatment of hyperthyroidism in children primarily involves the administration of antithyroid drugs that neutralize the effects of T3 and T4 on tissues. Symptoms of hyperthyroidism in children mainly include difficulty concentrating, nervousness, redness of the skin, rapid palpitations and swelling of the neck.
Do TSH problems also occur in men?
Although thyroid problems are usually a female affliction, men should also take care to be diagnosed for this condition. Hypothyroidism and hypothyroidism can affect them just as much as women. Symptoms of low TSH in men are the same as in women. In addition, men may notice a decrease in libido and impaired potency. When TSH levels are too high and hypothyroidism is present, men may notice the exact same symptoms in themselves as women. Numerous studies confirm that there is a certain group of men who are particularly vulnerable to thyroid problems. This includes men who have sustained sexual exposure, are over the age of 40, and have a genetic predisposition to thyroid diseases and disorders.
How much do TSH tests cost?
The determination of TSH levels can be performed free of charge if you receive a referral from a National Health Service doctor. Otherwise, the test will incur a small fee. However, prices vary depending on the laboratory. It is also worth remembering that in the case of an incorrect TSH concentration, the test is carried out again. The second time, however, the level of free thyroid hormones ft3 and ft4, as well as anti-thyroid antibodies (anti-TPO, anti-TG) should be carefully checked. In case of further abnormalities, the doctor may order an ultrasound of the thyroid gland. This is why proper diagnosis plays such an important role in thyroid diseases. Early diagnosis of diseases and implemented therapy can avoid many costs and health problems.
Conclusion
Understanding TSH is key to detecting and managing thyroid health. This hormone regulates vital processes like metabolism, mood, and organ functions. Imbalanced TSH levels—whether too high or too low—can signal serious conditions, emphasizing the importance of proper testing and diagnosis. Regular monitoring, early detection, and expert care can prevent complications and improve overall well-being. Remember, TSH levels vary by age and factors, so consult a specialist for accurate interpretation. Stay informed, as understanding thyroid health empowers better decisions for long-term health.
