What Is Considered A Bad Thyroid Level?

What Is Considered A Bad Thyroid Level? A normal range for TSH in most laboratories is 0.4 milliunits per liter (mU/L) to 4.0 mU/L. If your TSH is higher than 4.0 mU/L on repeat tests, you probably have hypothyroidism. Your doctor may also order a T4 test. What thyroid level is considered high? Experts don’t