Читать книгу The Healthy Thyroid: What you can do to prevent and alleviate thyroid imbalance - Patsy Westcott - Страница 49

There are two main types of hypothyroidism: primary, when the thyroid is the source of problems; and secondary, when a fault in the hypothalamus or pituitary has a knock-on effect on the thyroid.

• Primary hypothyroidism can be brought on by:

• thyroiditis (inflammation of the thyroid), a feature of Hashimoto’s thyroiditis (see page 49) and postpartum thyroiditis (PPT)

• surgical or medical treatment for an overactive thyroid (see Chapter 5) or surgery and/or radiotherapy for certain kinds of cancer

• prescription medications and over-the-counter drugs containing iodine (iodides), such as lithium for treating manic-depression, and some cough remedies

• congenital (inborn) problems affecting the thyroid, such as absence or abnormal development of the thyroid or errors of metabolism (see Chapter 9).

• Secondary hypothyroidism is caused by failure of the hypothalamic – pituitary – thyroid hormonal axis leading to deficient secretion of hormones by the hypothalamus or pituitary, caused by:

• known damage to the hypothalamus or pituitary as a result of previous surgery, meningitis, trauma or radiation to the brain

• the development of tumours or cysts.