TSH Result Explainer
Enter the required values below to run the educational estimation.
What is Thyroid Stimulating Hormone?
TSH is a pituitary hormone that regulates the production of thyroxine (T4) and triiodothyronine (T3) by the thyroid gland. Because of the feedback mechanism, a high TSH indicates that the pituitary is trying to stimulate an underperforming thyroid (hypothyroidism), while a low TSH indicates that excess thyroid hormones are suppressing TSH release (hyperthyroidism).
Evaluating High TSH Results
A TSH level above the reference range suggests hypothyroidism. This is commonly caused by Hashimoto's thyroiditis, an autoimmune condition, or can occur after thyroid surgery or radiation. Mildly elevated TSH with normal T4 levels is termed subclinical hypothyroidism.
Evaluating Low TSH Results
A TSH level below the reference range suggests hyperthyroidism. Common causes include Graves' disease, toxic multinodular goiter, or taking too high a dose of thyroid hormone replacement medication.
When to Seek Urgent Medical Attention
- Seek emergency care if you have abnormal TSH levels accompanied by severe chest pain, rapid or irregular heartbeats, high fever, or confusion.
Frequently Asked Questions
For most laboratories, the typical reference range for TSH is between 0.4 and 4.0 or 4.5 µIU/mL.
Yes. TSH levels normally decrease in the first trimester of pregnancy due to pregnancy hormones stimulating the thyroid directly.
