It’s estimated that as many as 25 million Americans have a thyroid problem, and half of them have no idea that they do. Hypothyroidism, or an under-active thyroid, accounts for 90% of all thyroid imbalances.

Here are 10 signs that you could have an underactive thyroid:

1. Fatigue after sleeping 8 to 10 hours a night or needing to take a nap daily.
2. Weight gain or the inability to lose weight.
3. Mood issues such as mood swings, anxiety or depression.
4. Hormone imbalances such as PMS, irregular periods, infertility and low sex drive.
5. Muscle pain, joint pain, carpal tunnel syndrome, or tendonitis.
6. Cold hands and feet, feeling cold when others are not, or having a body temperature consistently below 98.5.
7. Dry or cracking skin, brittle nails and excessive hair loss.
8. Constipation.
9. Mind issues such as brain fog, poor concentration or poor memory.
10. Neck swelling, snoring or hoarse voice.

How does you thyroid gland work?

Thyroid hormone production is regulated by a feedback loop between the hypothalamus, pituitary gland and the thyroid gland. Hypothalamic thyrotropin-releasing hormone (TRH) stimulates pituitary thyrotropin (TSH) synthesis and secretion.

In turn, TSH stimulates production and release of T4 and T3 from the thyroid gland. When enough T4 is produced, it signals to TRH and TSH that there is enough thyroid hormone in circulation and not to produce more.

About 85% of the hormone produced by our thyroid gland is T4, which is an inactive form of the hormone. After T4 is made, a small amount of it is converted into T3, which is the active form of thyroid hormone.

To complicate matters, T3 also gets converted into either Free T3 (FT3) or Reverse T3 (RT3). It’s the Free T3 that really matters in all of this, since it’s the only hormone that can attach to a receptor and cause your metabolism to read more