Hypothyroidism is due either to:

A. Deficiency of thyroid hormone production;

B. Failure of thyroid hormone to reach the tissues.

Both may operate together in varying degrees.

Deficiency of hormone production is due to:

1. Environmental toxins/deficiencies

2. Genetic thyroid failure

3. Thyroid failure secondary to pituitary insufficiency

4. Thyroid surgery

5. Treatment of previous over-activity

6. Major surgery

7. Tonsillectomy

8. Major trauma

9. Glandular fever

Failure of hormone to reach the tissues results from:

1. Receptor resistance, or failure

2. Dysfunction of T4-T3 conversion

3. Adrenal insufficiency

Dealing in turn with the therapeutic management of these problems, we may turn first to (A)Thyroid hormone production failure. This will be due to:

1. Environmental toxins and deficiency

a)Toxins

-A number of chemical agents tend to interfere with the manufacture of thyroid hormone. -Notables among these are:

-Poly chlorinated Biphenyls (Paints and wood preservatives)

-Resorcinol (Millet)

-Phthylate Esters (Plastics)

-Thiouracil (Cabbages, Turnips, Cassava.)

-Anthracin

-Bromoform

-Cyanides (Barbiturates)

-Fluorides

-Thiocyanates (Smoking)

-Caffeine

-Aspirin

-Lithium

-Amiodarones

The elimination of these from the diet may be desirable, if not always practical.

b)Nutritional Deficiencies

(i) Iodine. Endemically absent in certain inland areas e.g. (Peak District, UK)

(ii)Minerals, in particular:

Selenium

Iron

Magnesium

Zinc