High TSH levels can mean your thyroid is not making enough thyroid hormones, a condition called hypothyroidism. Low TSH levels can mean your thyroid is making too much of the hormones, a condition called hyperthyroidism.

What causes TSH levels to be high?

High TSH levels indicate hypothyroidism.

People develop hypothyroidism when their thyroid produces low levels of hormones. When the thyroid gland does not produce enough hormones, the pituitary gland produces more TSH to compensate. Symptoms of hypothyroidism include: fatigue.

What happens when your TSH is too high?

If your TSH levels are abnormally high, it could mean you have an underactive thyroid, or hypothyroidism. That's because it indicates your pituitary gland is producing more TSH in an effort to stimulate your thyroid to produce thyroid hormone, according to the Mayo Clinic.