Thyroid is a gland with a butterfly-like structure located in the front throat part of the neck. It forms part of the endocrine system, one of the body’s systems.
What is TSH?
The endocrine system is a system consisting of glands. The hormones they secrete into the blood enable the body to perform various functions and understand what the body will do or should do. For example, you feel hungry with the increased insulin hormone in the blood, and the endocrine system is responsible for the release of this hormone.
Another hormone that the endocrine system is responsible for is thyroid. Thyroid hormone is involved in regulating the metabolic rate that most people know. The body needs energy to work and perform its duties. For this reason, the nutrients entering the body are burned in various ways and converted into energy. This process of conversion into energy is called metabolic rate. The thyroid, which has control over the metabolic rate, can even indirectly affect weight, body temperature and muscle strength. Malfunctioning thyroids can affect nearly every organ in the body, including the heart, as well as metabolic rate. It is known that when thyroid hormone is high, body functions accelerate, and when it is low, body functions slow down.
Thyroid hormone is controlled by the pituitary gland located in the brain. The pituitary gland produces thyroid-stimulating hormone called TSH. Thanks to this TSH hormone, the thyroid gland knows how much thyroid it should produce. When the amount of thyroid in the blood decreases, your body’s need for thyroid increases. In response to this increased need, the pituitary gland secretes TSH, which stimulates the thyroid and ensures thyroid secretion. In this way, thyroid balance is maintained in the body. However, sometimes this balance may be disturbed due to various reasons. If the pituitary gland produces more TSH than it needs, it may affect the amount of thyroid in the body and therefore the functioning of the body.
In cases where it is not sure whether the thyroid gland is working properly or not, a TSH test can be performed. This test measures the amount of hormones in the blood to show whether the thyroid is producing the right amount of hormones. Depending on the results of this test, the TSH level may be higher than normal (hyperthyroidism) or lower than normal (hypothyroidism). This means there is a problem with the thyroid. It is not possible to understand what causes this problem with the TSH test. Some medications used may affect the functioning of the thyroid gland.
What should be the TSH value?
TSH value may not be the same for everyone. The normal TSH value varies depending on criteria such as age or pregnancy. The normal TSH value for a healthy person is as follows:
Babies 5 days old: 0.7 – 15.2 uIU/mL per milliliter
6- 90 days old babies: 0.72 – 11.0 uIU/mL.
4- 12 month old babies: 0.73 – 8.35 uIU/mL.
Children 1 to 6 years old: 0.7 – 5.97 uIU/mL.
Children 7 to 11 years old: 0.6 – 4.84 uIU/mL.
People ages 12 to 20: 0.51 – 4.3 uIU/mL.
Adults 21 to 99 years old: 0.27 – 4.2 uIU/mL.
During pregnancy, the TSH value may fluctuate constantly. TSH values considered normal during pregnancy are as follows:
First trimester (first 12 weeks): 0.18 – 2.99 uIU/mL.
Second trimester (13 to 27 weeks): 0.11 – 3.98 uIU/mL.
Third trimester (28 weeks to birth): 0.48 – 4.71 uIU/mL.
TSH and thyroid hormones also affect the development of the baby. For this reason, especially pregnant people are monitored by their doctors throughout the process. Each laboratory may have different reference ranges. Therefore, after having the test, be sure to show your results to a doctor.
What is TSH Test?
The TSH test is performed by examining the amount of TSH in the blood after your blood is drawn. Therefore, there is no need for preliminary preparation. If your doctor thinks that you have symptoms that indicate that the thyroid gland is underactive or overactive, he will direct you for a TSH test for control purposes. In addition, if you are thinking of pregnancy, you may want to have your TSH levels checked. If you use biotin (vitamin B7) as it may affect the results of the TSH test, be sure to inform your doctor about this.
According to the results of the TSH test, it is seen that the thyroid is working less or more. However, other tests are needed to find the cause. These tests:
T4 thyroid hormone test
T3 thyroid hormone test
It may include tests such as testing for thyroid antibodies.
As a result of these tests, it is understood which thyroid disease you have, such as Graves and Hashimoto, and the necessary medication or diet treatment can be applied.
What is High TSH?
Increased TSH level in the blood is associated with low amount of thyroid. When the thyroid gland does not produce enough thyroid, the pituitary gland continues to secrete TSH. This causes the amount of TSH in the blood to increase. This condition is called hypothyroidism. Hashimoto’s disease, which disrupts the working balance of the thyroid gland, is one of the conditions that causes hypothyroidism. Although reference ranges vary between laboratories, elevated TSH is generally considered at values higher than 4-5 mU/L.
Hypothyroidism treatment aims to increase underactive thyroid hormones with medications. The course of treatment usually includes levothyroxine derivative drugs. Levothyroxine should be taken once a day in the morning on an empty stomach and at least 30 minutes before the first meal. Your doctor will adjust the dose of the medicine correctly during regular follow-up.
What are the symptoms of high TSH?
Some symptoms of high TSH, also called hypothyroidism, are:
Constipation
Sudden and unexplained weight gain
Depression
Decrease in sexual desire
Frequent and heavy menstrual periods
Numbness or tingling in hands and feet
Weakness
Intolerance to very hot or very cold.
Having one or more of the above symptoms does not mean you have hypothyroidism. However, it would be beneficial to contact the nearest health institution and discuss your symptoms with your doctor.
Why Does TSH Rise or Fall?
If your TSH value is higher or lower than normal, this may not always be due to a medical condition. Your doctor considers several factors when interpreting your results.
Age: As can be seen from the table of normal TSH values above, TSH tends to increase with age. Especially in those aged 80 and above, TSH values may be slightly high. However, there is no health-related reason for this.
Pregnancy: Another condition that causes fluctuations in thyroid hormone is pregnancy. It generally tends to decrease in the early stages of pregnancy and increase later.
Severe Disease: Even if there is no thyroid-related disease, TSH levels may temporarily decrease in situations that stress the body.
What is Low TSH?
A low TSH level in the blood means that the thyroid gland is overactive. This condition is called hyperthyroidism. An overactive thyroid gland also causes the metabolism to accelerate. Some causes of hyperthyroidism may be:
Graves’ disease, which causes excessive hormone secretion from the thyroid
thyroid nodules
Excessive salt consumption
Using too much thyroid hormone medication
Using too many supplements (Especially vitamin B)
Using steroids, opioid-derived painkillers
What are the symptoms of low TSH?
Symptoms of hyperthyroidism generally include changes that develop due to acceleration of metabolism:
- Palpitations (increased heart rate)
- Unwanted, unexplained and sudden weight loss
- Changes in defecation (usually having to go to the toilet more frequently or diarrhea)
- Irregularity in menstrual periods
The main goal of hyperthyroidism treatment is to lower thyroid hormone levels. For this
- Drug treatments such as beta blockers and antithyroidism
- Taking radioactive iodine-131 in liquid or capsule form (it destroys thyroid-producing cells in the body)
- Treatment options such as surgical removal of the thyroid gland may be applied.
