Is fasting required for t3, t4 tsh test

What is a TSH Test?

TSH stands for thyroid stimulating hormone. Another name for it is thyrotropin. A TSH test is a blood test that measures this hormone.

A TSH level that is too high or too low may be a sign of a thyroid problem.

The thyroid is a small, butterfly-shaped gland in the front of your neck.

What is considered a dangerously high tsh level

Your thyroid makes hormones that control how your body uses energy. Thyroid hormones affect nearly every organ and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and even your mood.

If you don't have enough thyroid hormones in your blood, many of your body functions will slow down.

Normal tsh levels by age

But if you have too much, many body functions will speed up.

Your thyroid is controlled by a gland in your brain called the pituitary gland. The pituitary gland makes thyroid-stimulating hormone (TSH). TSH tells your thyroid how much thyroid hormone it needs to make.

If the thyroid hormone level in your blood is too low, your pituitary gland makes larger amounts of TSH to tell your

what does a tsh test show