Thyroid is produced by the thyroid gland in response to stimulation by the pituitary gland. Like testosterone production, the pituitary gland works like a thermostat. It senses the level of thyroid (T4) in the blood. As it senses the body needs more, it puts out thyroid stimulating hormone (TSH) to stimulate the thyroid to produce more T4. As T4 levels rise to healthy levels the pituitary shuts the TSH down. As the body ages, the pituitary produces less TSH and the thyroid produces less T4. The result is a low level of thyroid hormone.

Symptoms of low thyroid

• Fatigue
• Low body temperature -- general sensitivity to cold
• Thinning hair on the head
• Loss of body hair
• Dry skin and hair and brittle nails
• Anxiety and irritability – Sleep problems
• Depression
• High cholesterol
• Mental fogginess
• Metabolic rate falls – weight gain – increased body fat
• Constipation
  

· Susceptibility to hardening of the arteries

For those interested in reading more:

The first paragraph is only half of the story.

T4 accounts for only 20% of thyroid function – it passes through the blood brain barrier into the brain. The other 80% of T4 should be broken down by the body into T3 and its functional form T3 free. As the body ages, chemical changes take place that inhibit this breakdown.

The problem: many/most doctors only measure the feed back mechanism described in paragraph 1 above -- T4 and TSH. If there is treatment, it involves giving synthetic T4. the doctors seldom check T3 and thereby miss 80% of thyroid function.

It is quite common for us to see men who have been checked by their family doctor and/or are being treated with T4 but are showing all the symptoms of low thyroid. We check their T3 free and find it to be low.

In treating thyroid deficiency, we use desiccated thyroid that contains both T4 and T3. We want to see the T3 free somewhere between 350pg and 425pg.