A test for thyroid-stimulating hormone is done to:
Find out whether the thyroid gland is working properly.
Find the cause of an under-active thyroid gland.
Keep track of treatment results for people with hyperthyroidism or hypothyroidism
Hypothyroidism: An under-active thyroid gland. Symptoms include weight gain, tiredness, constipation, and a feeling of being too cold.
Hyperthyroidism: An overactive thyroid gland. Symptoms include weight loss, rapid heart rate, nervousness, diarrhea, a feeling of being too hot, and irregular menstrual periods.
A normal thyroid range is 0.350 - 5.500 uIU/mL.