Normal thyroid stimulating hormone test results range from 0.4 to 4.0 milli-international units per liter of blood but may vary among laboratories due to differing measurements or test samples, according to MedlinePlus. The TSH test is a standard test used to measure thyroid function.
A doctor orders a TSH test if there are symptoms indicating an overactive or underactive thyroid gland, states MedlinePlus. High thyroid hormone levels, or hyperthyroidism, may present in cases of Grave's disease, thyroiditis or a goiter that contains abnormal growths, notes WebMD. Conversely, hypothyroidism may result from destruction or damage to the thyroid gland by surgery or radiation, pituitary gland disease or thyroid disease.