Time to talk thyroid with my blogger buds. Here's the symptoms of hypothyroid (low thyroid):

-fatigue
-weakness
-weight gain
-difficulty losing weight
-coarse, dry hair,
-dry skin
-hair loss
-cold intolerance (you can’t tolerate cold temperatures like those around you)
-muscle cramps and frequent muscle aches
-constipation
-depression
-irritability
-memory loss
-abnormal menstrual cycles
-decreased libido

Here are some reasons why your thyroid might be low:

Defect #1 – Pituitary
If the pituitary is not functioning correctly, it cannot produce adequate amounts of TSH to stimulate their thyroid. This is most often due to suppression of the pituitary by cortisol.

Defect #2 – Thyroid
This defect is medically referred to as primary hypothyroidism, which is the one dysfunction doctors actually look for. However, the reference range for TSH is so wide, many people with this defect will be missed. Also, many people with this defect have an autoimmune thyroid condition (see Bonus Defect below).

Defect #3 – Thyroid Binding Globulin (TBG)
If there is too much thyroid binding globulin, thyroid hormone would be bound and unable to get into the cell. Thyroid function may be perfect, but if it’s all bound, it can’t get into the cells. This is most commonly caused by elevated estrogen in both men and women.

Defect #4 – Thyroid Binding Globulin (TBG)
If there is not enough thyroid binding globulin, there can be too much free thyroid hormone available for cells. While this doesn’t sound like a problem, elevated free thyroid hormone shuts down receptor sites and can therefore cause hypothyroid symptoms, despite high free thyroid hormone levels. The most common cause of this is elevated testosterone in both men and women.

Defect #5 – Conversion
If inactive T4 cannot be converted to T3, there will not be enough active thyroid hormone for cells. This can be due to a number of issues including certain mineral deficiencies (i.e. selenium), elevated cortisol or excessive oxidative stress.

Defect #6 – Dysbiosis
It is difficult to know the degree that dysbiosis can cause thyroid physiology issues. Because twenty percent of thyroid hormone is converted to active T3, if there is significant gut issues, or lack of healthy gut bacteria, there may be low thyroid symptoms.

Defect #7 – Thyroid Receptor
If thyroid hormone cannot get into the cell there will be low thyroid symptoms despite thyroid hormone levels in the body. Receptor site defects can be caused by elevations in cortisol, homocysteine or vitamin A deficiency.

Defect #8 – Autoimmune Thyroid
In industrialized countries, the vast majority of primary hypothyroidism issues (Defect #2) are due to an autoimmune condition called Hashimoto’s syndrome. If this is the case, it is no longer a thyroid issue, but rather an immune system issue and must be managed as such.