Causes of high thyroid-stimulating hormone, or TSH, levels include hypothyroidism, excess anti-thyroid medication and a tumor in the pituitary gland, according to LabTestsOnline. TSH is produced in the pituitary gland, a... More »

A value less than 0.4 milli-international units per liter constitutes a low TSH level, according to MedlinePlus. Low TSH is sometimes desirable for patients who are being treated for a pituitary disorder or thyroid cance... More »

www.reference.com Health Medical Ranges & Levels

According to About.com, low levels of TSH, or thyroid-stimulating hormone, occur when the pituitary gland shuts down TSH production due to high levels of thyroid hormone in the blood. The low levels of TSH are the pituit... More »

Causes of low thyroid-stimulating hormone, or TSH, levels include hyperthyroidism; a damaged pituitary gland that is unable to make TSH, called secondary hypothyroidism; and taking excess thyroid medicine when treating a... More »

According to WebMD, high TSH (thyroid-stimulating hormone) levels indicate an underactive thyroid gland (hypothyroidism). Common symptoms include feeling weak, tired or depressed, sensitivity to cold, constipation, britt... More »

Causes of high levels of thyroid-stimulating hormone include hypothyroidism, a tumor in the pituitary gland, or a need to increase the amount of thyroid hormone medicine, according to WebMD. The pituitary gland produces ... More »

According to About.com, low levels of TSH, or thyroid-stimulating hormone, occur when the pituitary gland shuts down TSH production due to high levels of thyroid hormone in the blood. The low levels of TSH are the pituit... More »