Your thyroid stimulating hormone (TSH) level is normal. Normal is between 0.3 and 4.0, with each laboratory reporting different ranges.

The difference between your two values is only 0.06. This is not significant. Even a slightly larger difference between the two would not be surprising. The amount of thyroid stimulating hormone in the blood does vary somewhat.

Here’s what happens in our bodies. Thyroid stimulating hormone is made by the pituitary gland. This small gland sits at the bottom of the brain. The gland sends TSH into the blood stream. When TSH reaches the thyroid gland, it causes the thyroid to make thyroid hormone.

The amount of thyroid hormone in the blood is relatively constant. If the level is normal, TSH will be normal. If the blood level of thyroid hormone drops below normal, the pituitary gland gets the message to make and send out more TSH. The TSH level rises.

If the thyroid hormone blood level is too high, the pituitary gland slows down and makes little or no TSH. The TSH level gets very low.

A TSH blood test is very useful for people who take thyroid hormone pills for an under active thyroid gland. A normal TSH, such as yours, means the dose of thyroid is just right.