Whenever T3 and T4 hormone levels become out of balance many negative symptoms can occur. For example, if the thyroid produces too much T4, it is known as hyperthyroidism. TSH levels are usually lower in this instance because the pituitary gland does not detect a need for more T4. All of the systems managed by the thyroid, like the metabolism, work extra hard because of the excess T4. Symptoms of hyperthyroidism include:
- Sudden and quick weight loss
- Irregular or rapid heartbeat
- More frequent bowel movements
- Swollen neck (near the base, where the thyroid is)
The TSH and T4 tests provided in this panel can be used in conjunction to diagnose hyperthyroidism. TSH levels will likely read lower than normal, and T4 levels should be on the high end.
The opposite of hyperthyroidism, hypothyroidism, occurs when the thyroid does not produce enough T4 necessary to properly manage the bodily functions it is responsible for. When this happens, the pituitary gland reacts by releasing abnormally high amounts of TSH to signal to the thyroid to produce more T4. The symptoms of hypothyroidism include:
- Feeling cold often
- Weight gain
- Overall weakness
- Aches and pains
- Slowed heart rate
- Poor memory
While the lack of T4 is the cause of hypothyroidism, the high TSH levels that the body releases in response to this are what physicians look at to help confirm the diagnosis.
This test panel is performed by drawing blood. You do not need to fast for this test panel.