THYROID FUNCTION TESTS: TSH, T 3 , AND T 4

 

What is the Thyroid?

The thyroid is a small gland in the neck that regulates your body's metabolism. If you

have an overactive thyroid (hyperthyroidism), you could notice symptoms like feeling hot,

an irregular heartbeat, or unusual weight losses. With an underactive thyroid

(hypothyroidism), you might experience symptoms like weight gain, fatigue, dry skin, and

hair loss.

 

Why Would I Need it Checked?

If you've lost or gained a lot of weight in a short period of time or have an enlarged area

on your neck (commonly referred to as a goiter), your doctor will probably want to check

your thyroid levels. Women are more prone to thyroid disease than men, and it can be

genetically linked.

 

What Tests Might Be Ordered?

A TSH test will measure the amount of thyroid-stimulating hormone your body is

producing. This hormone is produced in the pituitary gland, located at the base of the

neck, just below the brain. The hormone stimulates your thyroid cells and causes them

to produce T3 (triiodothyronine) and T4 (thyroxine), which are the thyroid hormones.

 

What Do the Results Indicate?

If your TSH level is high, you may have a thyroid gland which isn't producing enough T3

and T4, resulting in you feeling tired all the time. Your diagnosis would be

hypothyroidism.

 

If your TSH is low, your thyroid gland may be producing too much T3 and T4, raising your

metabolism to unusual levels, making you thin and hyperactive. You would then be

diagnosed with hyperthyroidism.