Thyroid stimulating hormone is produce by the pituitary gland. The thyroid gland manufactures two important hormones, T4 and T3, which are very important for a proper functioning of many systems in the body. Thyroid stimulating hormone of the pituitary gland has the role to stimulate the production of these two hormones. When one has the problem with his/her metabolism, thyroid stimulating hormone is then tested.
Low levels of thyroid stimulating hormone
The normal levels of this hormone vary in certain countries. In some countries, the normal level of this hormone is from 0.5 to 5.5, while in some others it is between 0.3 and 3.3. Therefore, there are many speculations about the normal level of thyroid stimulating hormone. The thyroid stimulating hormone does not keep the same level throughout the day. It is the lowest at noon and the highest at midnight. The difference between the lowest and highest levels of TSH is approximately even 2 points.
When a test is done and when it shows low levels of this hormone, every person should logically conclude that the thyroid dose should be increased. Contrary to that, the doctor decreases the thyroid dose. The low levels of thyroid stimulating hormone indicate that the thyroid gland is already overactive. Therefore, low thyroid stimulating hormone levels are the main symptoms of hyperthyroidism or hyperactive thyroid gland. On the other hand, when the test shows high thyroid stimulating hormone levels, it is the main indicator of hypothyroidism or inactive or low thyroid gland.
Test of thyroid stimulating hormone
Since, TSH is produced by the pituitary gland and not by the thyroid gland, there are cases when the thyroid gland functions well while the pituitary gland, which is controlled by hypothalamus in the brain, malfunctions due to some reasons. Therefore, TSH test should be performed together wit T4 and T3 tests.
Symptoms and causes of low levels of thyroid stimulating hormone
The symptoms of this condition are very much the same as the symptom of overactive thyroid gland. Therefore, the most frequent warning signs are tiredness, nervousness, heart palpitations and muscle weakness. Furthermore, insomnia, increased bowel movement and weight loss, as well as hair loss and trembling hand may also occur. In the majority of cases, the main cause of this condition is Grave’s disease. Another potential cause for the occurrence of low TSH levels is nodular thyroid disease. Thyroiditis is the medical term for the inflammation of the thyroid gland and it can also be a potential cause for the low TSH levels.