What Is A Normal TSH Level?

It may be easy to overlook the thyroid, but it's important to your health. The thyroid is a small butterfly-shaped gland located in the neck, according to UCLA Health. It releases two types of thyroid hormone: thyroxine (T4) and triiodothyronine (T3). Proper levels of these hormones are necessary for healthy functioning, and the pituitary gland is responsible for maintaining homeostasis. When thyroid hormone is low, the pituitary gland produces thyroid-stimulating hormone (TSH), triggering the thyroid to make more hormones. When thyroid hormone is normal or high, TSH is shut off. 

Several chronic health conditions are linked to thyroid disorders, and you'll need your doctor to diagnose you. To measure TSH, your doctor may order a blood test, according to Healthline. You won't need to do anything special to prepare, though you may be asked to discontinue the use of certain medications like lithium, dopamine, biotin, potassium iodide, and prednisone. Always speak with your doctor before discontinuing any medications. Your doctor will examine your results to assess whether or not they are within a healthy range and account for other important considerations. 

Healthy TSH ranges and factors that affect it

Normal TSH levels should fall between 0.45 and 4.5 milli-international units per liter (mIU/L), according to Healthline. High TSH levels mean that the thyroid isn't producing enough thyroid hormone, often called hypothyroidism. Low TSH levels indicate that the thyroid is overactive, also called hyperthyroidism. Some sources differ in what defines a maximum normal level, though. A 2013 study published in The Journal of Clinical Endocrinology & Metabolism recommends a range between 0.45 and 4.12 mIU/L.

This range also fluctuates based on factors such as age, sex, and life stage, according to Healthline. In the first month of life, TSH levels are high, then decrease as you enter adulthood. Later in life, TSH levels will rise again. Women are more prone to abnormal levels of TSH when menstruating, giving birth, and going through menopause. If men have abnormal levels, they are more likely to have issues with fertility. See your healthcare provider if you're concerned about your TSH levels.